Which of these is NOT an example of a reference direction?
A. +
B. S
C. down
D. 2 E

NEED HELP ASAP!

Answer:

The right answer is 160j

Dane is holding an 8 kg box 2 meters above the ground. The box's gravitational potential energy will be 160 joules.

The term gravitational potential energy refers to the energy that an item stores as a result of its elevation above the Earth's surface. This energy is a result of an object being subjected to gravity.

Potential energy is transformed into kinetic energy when a stone falling from a height impacts the earth's surface.

According to the question, the given values are :

Mass, m = 8 kg

Height, h = 2 meters above the ground and,

g = 10 N/kg

Gravitational potential energy = mgh

P = 8×10×2

P = 160 J.

Hence, gravitational potential energy is 160 J.

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a) The net force on the system is 883.5 N

b) The tension in the rope is 505.5 N

c) The applied force is 1875.8 N

Explanation:

a)

We start by considering the whole system snowmobile+sled. We can apply Newton's second law:

[tex]\sum F = (m+M)a[/tex]

where

[tex]\sum F[/tex] is the net force on the system

m = 150 kg is the mass of the sled

M = 315 kg is the mass of the snowmobile+rider

[tex]a=1.9 m/s^2[/tex] is the acceleration

Substiting the values into the equation, we find the net force:

[tex]\sum F=(150+315)(1.9)=883.5 N[/tex]

b)

Now we consider only the forces acting on the sled. Again, we apply Newton's second law:

[tex]T-F_f = ma[/tex]

where:

T is the tension in the rope, which pulls the sled forward

[tex]F_f[/tex] is the frictional force acting on the sled, which acts backward

m = 150 kg is the mass of the sled

[tex]a=1.9 m/s^2[/tex] is the acceleration

The force of friction on the sled is given by

[tex]F_f = \mu mg[/tex]

where

[tex]\mu=0.15[/tex] is the coefficient of friction of the sled on ice

m = 150 kg

[tex]g=9.8 m/s^2[/tex] is the acceleration of gravity

Substituting and solving for T, we find:

[tex]T-\mu mg = ma\\T=m(a+\mu g)=(150)(1.9+0.15 \cdot 9.8)=505.5 N[/tex]

c)

Now we consider instead the forces acting on the snowmobile+rider only. Applying again Newton's second law,

[tex]F-F_F-T = Ma[/tex]

where

F is the applied force, which pushes the snowmobile forward

[tex]F_F[/tex] is the force of friction acting backward on the snowmobile

T = 505.5 N is the tension in the rope, which pulls the snowmobile backward

M = 315 kg is the mass of the snowmobile+rider

[tex]a=1.9 m/s^2[/tex] is the acceleration

The force of friction on the snowmobile is given by

[tex]F_F = \mu Mg[/tex]

where

[tex]\mu=0.25[/tex] is the coefficient of friction of the snowmobile on ice

m = 315 kg

[tex]g=9.8 m/s^2[/tex]

Substituting and solving for F, we find the applied force:

[tex]F=Ma+\mu Mg+T=(315)(1.9)+(0.25)(315)(9.8)+505.5=1875.8 N[/tex]

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Final answer:

People should pay attention to scientists when making decisions because they utilize an evidence-based process, with observation and peer review, to discern truths about the natural world. The scientific method underpins the reliability of their findings, which can help inform well-grounded decisions.

Explanation:

People should pay attention to scientists when making decisions because scientists use observation and peer review as a part of the scientific method. This process involves making detailed observations, formulating hypotheses, conducting experiments, and drawing conclusions based on evidence. Scientists' claims are supported by evidence that can be examined and experiments that can be replicated, ensuring reliability and validity in their findings.

Additionally, scientists often work in a community where peer-review plays an essential role in validating studies and research before they are widely accepted. Although the process of science may not be perfect due to factors such as human error or bias, the method remains the best we have for systematically understanding the natural world. The iterative nature of science, with its self-correcting mechanisms like peer-review and replication, often leads to a gradual refinement of knowledge.

Therefore, scientists, through their evidence-based approach, are considered reliable sources for informing decisions related to their field of study. Considering science in decision-making processes also ensures that conclusions are rooted in systematically acquired data, as opposed to unfounded claims or assumptions.

Final answer:

Scientists use observation and peer review to ensure the reliability of their findings, making their conclusions more trustworthy than mere opinion or guesswork. Furthermore, science is a democratic and cumulative process, where open debates and the use of systematic data collection lead to continual progress and refinement of knowledge.

Explanation:

People should pay attention to scientists when making decisions because scientists use observation and peer review. This process involves careful measurement, experimentation, and scrutiny by other experts in the field. Through this rigorous method, scientific claims become more reliable and can predict real outcomes more accurately than personal opinions or anecdotes. As our understanding builds upon prior knowledge, we can progress further in our comprehension of the world.

Moreover, science is a democratic process. Scientists must be skeptical and discuss their observations and theories openly, subjecting their findings to the critical analysis of their peers. This discourse allows for the best data to emerge and for errors to be exposed and corrected. Additionally, scientific advancements are cumulative. We learn from past discoveries and then develop new understandings based on the foundations laid by those who came before us.

Political scientists, similar to natural scientists, rely on data to make informed predictions. They use systematic data collection and analysis to understand patterns and make forecasts about future events rather than relying solely on technology or random chance.

The energy stored in a spring is

E = 1/2 (k x²)

' k ' is the spring constant . . . the number of newtons of force it takes to stretch or compress the spring by one meter from its relaxed length

' x ' is the distance the spring is stretched or compressed

For this problem, we know ' E ' and ' x ', and we need to find ' k '.

E = 1/2 (k x²)

1,000 = 1/2 (k) (0.025²)

1,000 = 1/2 (k) (0.000625)

Multiply each side by 2 :  

2,000 = (k) (0.000625)

Divide each side by 0.000625:

(2,000) / (0.000625) = k

k = 3,200,000

The spring constant is 3.2 x 10⁶ Newtons per meter .

This is a very stiff spring !  My calculator says that if you want to stretch it just 1 inch, you have to pull it with a force of 18,285 pounds ! !  If such a spring exists, it might be used as part of the suspension for a tank or a concrete truck.

The spring constant of the given spring is equal to  3.2 × 10⁶ N/m.

Hooke's law can be explained as a law that states that the force (F) needed to extend or compress a spring by distance linearly with respect to that distance along a straight line.

The spring force can be expressed in the form of an equation:

F = -kx,

where k is a spring constant and x  is the possible deformation of the spring. The negative sign indicates that the spring will return to its original shape or position.

The energy stored in the spring when it is compressed is given by:

E = (1/2)kx²

Given, the energy stored in the spring when it is compressed, E = 1000J

The distance by which spring is compressed, x = 2.5 cm = 0.025 m

1000 =  (1/2)×k (0.025)²

k = 3.2 × 10⁶N/m

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46.67 m/s²

We are given;

we are supposed to calculate the acceleration of the rocket;

Therefore;

F = Ma

In this case;

Rearranging the formula

a = F ÷ m

  = 140 N ÷ 3 kg

  = 46.67 m/s²

Thus, the acceleration of the rocket is 46.67 m/s²

Answer:

As the skydiver falls to the Earth, she experiences positive acceleration only due to gravity.

Explanation:

As the skydiver falls to the Earth, she experiences friction in the form of air resistance which tries to slow her down and is proportional to the her velocity. So it cannot have a positive acceleration as it acts in opposite direction to slow her down.

Inertia during skydiving is experienced when we open an parachute, the parachute slows down the speed of are descent hence changing our inertia of motion with a velocity.

Only the Earth's, gravitational field has an positive acceleration as it pulls us towards the Earth, hence increasing our velocity.

The final speed of the safe is 51.7 m/s

Explanation:

The motion of the safe is a free fall motion, which is a motion at constant acceleration ([tex]g=9.8 m/s^2[/tex], towards the ground). Therefore, we can apply the following suvat equation:

[tex]v^2-u^2=2as[/tex]

where

v is the final velocity

u is the initial velocity

a is the acceleration

s is the displacement

In this problem we have (taking downward as positive direction):

u = 11.0 m/s

[tex]a=g=9.8 m/s^2[/tex]

[tex]s=1.3\cdot 10^2 m= 130 m[/tex] is the vertical displacement (the height of the building)

Solving for v, we find the final velocity (and so, the final speed):

[tex]v=\sqrt{u^2+2as}=\sqrt{11.0^2+2(9.8)(130)}=51.7 m/s[/tex]

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The velocity of the rocket is 7.8 m/s

Explanation:

We can solve the problem by using the law of conservation of momentum: in fact, in absence of external forces, the total momentum of the rocket+fuel system must be conserved.

Before the launch, the total momentum of the system is zero, since the rocket and the fuel are at rest:

[tex]p=0[/tex]

After the launch, the total momentum is

[tex]p=MV+mv[/tex]

where

M = 4.0 kg is the mass of the rocket

V is the velocity of the rocket

m = 50.0 g = 0.050 kg is the mass of the fuel ejected

v = -625 m/s is the velocity of the fuel (taking "backward" as negative direction)

Since the total momentum is conserved, we have

[tex]0=MV+mv[/tex]

So we can solve the equation to find V, the velocity of the rocket:

[tex]V=-\frac{mv}{M}=-\frac{(0.050)(625)}{4.0}=+7.8 m/s[/tex]

And the positive sign means the rocket moves forward.

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The velocity of the rocket after the fuel has burned is 7.81 m/s.          

From law of conservation of Momentum,

                         [tex]MV=mv[/tex]

Where M is mass of rocket and V is velocity of rocket

And m is mass of burned fuel and v is speed of fuel.

Given that, [tex]M=4Kg,m=50g=0.05Kg,v=625m/s[/tex]

Substitute values in above equation,

                  [tex]4*V=0.05*625\\\\V=\frac{0.05*625}{4} =7.81m/s[/tex]

Hence, the velocity of the rocket after the fuel has burned is 7.81 m/s.              

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Answer:

No, the Sunlight won't get extinct.

Explanation:

It is not true as the sun will not be extinct due to the usage of sunlight by all the living creatures but definitely due to the climatic conditions and several bad activities of humans. It would become extinct or become a red big giant that would destroy the planet.

Scientists have estimated the life on the planet that is 1.5 billion years. Earth would get destroyed much prior to sun. After 7.5 billion years, sun would turn out to be as large as a big giant.

These are the reasons why sun will get extinct but not because of its usage.

The specific heat capacity of concrete is [tex]3.0 J/(g^{\circ}C)[/tex]

Explanation:

When a certain amount of energy Q is supplied/given off to/from a sample of substance with mass m, the temperature of the substance increases/decreases by an amount [tex]\Delta T[/tex], according to the equation

[tex]Q=mC_s \Delta T[/tex]

where

m is the mass of the substance

[tex]C_s[/tex] is the specific heat capacity of the substance

[tex]\Delta T[/tex] is the change in temperature of the substance

In this problem, we have:

m = 1 kg = 1000 g is the mass of the concrete slab

[tex]Q = -12,000 J[/tex] is the amount of energy lost by the slab

[tex]\Delta T = 30-26= -4^{\circ}C[/tex] is the change in temperature of the slab

Solving the equation for [tex]C_s[/tex], we find the specific heat capacity of concrete:

[tex]C_s = \frac{Q}{m \Delta T}=\frac{-12,000}{(1000)(-4)}=3.0 J/(g^{\circ}C)[/tex]

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Final answer:

The specific heat capacity of concrete is calculated using the heat transfer formula Q = mcΔT, and the given values of 1 kg mass, a temperature change of 4°C, and a heat loss of 12,000 J. The specific heat capacity is found to be 3,000 J/kg/°C.

Explanation:

To determine the specific heat capacity of concrete, we start by using the formula for heat transfer:

Q = mcΔT

where Q is the heat energy transferred (in joules, J), m is the mass (in kilograms, kg), c is the specific heat capacity (in J/kg/°C), and ΔT is the change in temperature (in °C). In this scenario, we are given that a 1kg slab of concrete loses 12,000J of heat when it cools from 30°C to 26°C.

The change in temperature (ΔT) is the final temperature minus the initial temperature, that's 26°C - 30°C = -4°C. We are solving for c, the specific heat capacity of concrete. It is possible to solve for c by rearranging the heat transfer equation:

c = Q / (mΔT)

We substitute the known values into this equation:

c = 12,000 J / (1 kg × -4°C)

c = 12,000 J / -4 kg°C

c = -3,000 J/kg/°C

The negative sign indicates that the concrete is losing heat, however, the specific heat capacity is a positive value. Therefore, the specific heat capacity of concrete is 3,000 J/kg/°C.

The resistance of the lightbulb connected to a 60 Hz power source and using an average power of 38.8 W, with a maximum voltage of 156 V, is approximately 312.4 Ω.

To find the resistance of the lightbulb, we must first establish the effective value of the voltage, since the given voltage is the maximal one. For sinusoidal alternating currents (like the standard electrical supply), the effective or 'root mean square' voltage is the maximum voltage divided by the square root of 2 (approximately 1.414). So, the effective voltage (Vrms) is 156 V / √2 = 110.3 V.

Next, we use the formula for power P = V^2 / R, where V is the effective (rms) voltage and R is the resistance. Looking for R, we rearrange the equation to get R = V^2 / P. Substituting the given values we get R = (110.3 V)^2 / 38.8 W = 312.4 Ω. Therefore, the resistance of the light bulb is approximately 312.4 Ω.

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The resistance of a light bulb is approximately 313.57 Ω. This is calculated by converting maximum voltage to RMS voltage and applying the power formula P = V²/R.

To solve this, we need to follow these steps:

First, convert the maximum voltage (Vmax) to the root mean square (RMS) voltage (Vrms) using the formula [tex]V_{rms} = V_{max} / \sqrt2[/tex]. So, [tex]V_{rms} = 156 V / \sqrt2 = 110.3 V[/tex]

Use the power formula that relates power (P), voltage (V), and resistance (R):
[tex]P = V_{rms}^2 / R[/tex]
Rearrange it to solve for resistance (R):
[tex]R = V_{rms}^2 / P[/tex]

Substitute the values:
R = (110.3 V)² / 38.8 W
R ≈ 313.57 Ω

Thus, the resistance of the light bulb is approximately 313.57 Ω.

The horizontal distance covered by the ball is 75.8 m

Explanation:

The motion of the ball in this problem is a projectile motion, so it follows a parabolic path which consists of two independent motions:

- A uniform motion (constant velocity) along the horizontal direction

- An accelerated motion with constant acceleration (acceleration of gravity) in the vertical direction

First of all, we consider the vertical motion to find the time of flight of the ball. Using the suvat equation:

[tex]s=ut+\frac{1}{2}gt^2[/tex]

where

s = 45 m is the vertical displacement of the ball

t is the time of flight

u = 0 is the initial vertical velocity of the ball

[tex]g=9.8 m/s^2[/tex] is the acceleration of gravity

Solving for t,

[tex]t=\sqrt{\frac{2s}{g}}=\sqrt{\frac{2(45)}{9.8}}=3.03 s[/tex]

Now we know that the ball moves horizontally with a constant velocity of

[tex]v_x = 25 m/s[/tex]

So, the horizontal distance covered by the ball during its flight is

[tex]d=v_x t = (25)(3.03)=75.8 m[/tex]

So the ball lands 75.8 m far from the base of the cliff.

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The ball hits the ground approximately 75.30 meters away from the base of the cliff.

Since the baseball is thrown horizontally, the initial vertical velocity will be zero. The time it takes for the ball to fall can be found using the equation h = (gt^2)/2, where h is the vertical displacement and g is the acceleration due to gravity. Plugging in the values, we get t = sqrt(2h/g). The horizontal distance can be found using the equation d = v*t, where d is the distance and v is the horizontal velocity. Plugging in the values, we get d = v*t. Calculating the values, t = sqrt(2*45/9.8) = 3.01 seconds and d = 25 * 3.01 = 75.30 meters.

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Answer:

d

Explanation:

this is the order of the moons ( you can look it up too)

The correct sequence of moon phases is: new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent. The cycle follows the moon as it appears illuminated from Earth.

The correct sequence of the moon phases is: new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and waning crescent. The cycle starts with the new moon when the moon is not visible from Earth. The moon then enters the waxing crescent phase when a thin sliver of the moon becomes visible. The first quarter is when half of the moon is illuminated. This is followed by the waxing gibbous phase when more than half but not fully illuminated. The full moon phase is when the entire face of the moon is illuminated. The moon then begins to wane and less of it is illuminated each night. Waning gibbous phase comes first, followed by the third quarter phase when half of the moon is illuminated. The cycle ends with the waning crescent phase when again only a sliver of the moon is visible before transitioning back to a new moon.

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The length of the side of the cube is 4 cm

Explanation:

The density of the cube is given by:

[tex]\rho=\frac{m}{V}[/tex]

where

m is the mass of the cube

V is its volume

Also, the volume of the cube is given by

[tex]V=L^3[/tex] (2)

where L is the length of each side.

For the cube in this problem we have:

m = 128 g

[tex]\rho=2 g/cm^3[/tex]

From the first equation, we find the volume of the cube:

[tex]V=\frac{m}{\rho}=\frac{128}{2}=64 cm^3[/tex]

And now we use eq.(2) to find the length of the side:

[tex]L=\sqrt[3]{V}=\sqrt[3]{64}=4 cm[/tex]

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The length of each side of a cube with a mass of 128 grams and a density of 2 grams per cubic centimeter is 4 centimeters.

To find the length of each side of a cube with a mass of 128 grams and a density of 2 grams per cubic centimeter, we can use the formula for density which is mass divided by volume. Since density is given in grams per cubic centimeter (g/cm3), we'll keep the mass in grams and calculate the volume in cubic centimeters. First, we calculate the volume of the cube by dividing the mass by the density (Volume = Mass / Density).

Volume = 128g / 2g/cm3 = 64 cm3

Because the volume of a cube is also the cubic of the length of its side (Volume = side3), we can now find the length of one side by taking the cube root of the volume.

Length of one side = \3\sqrt{64 cm3} = 4 cm

Therefore, each side of the cube is 4 centimeters in length.

The acceleration of gravity on the surface of Pluto is [tex]0.61 m/s^2[/tex]

Explanation:

The acceleration of gravity at the surface of a planet is given by the equation:

[tex]g=\frac{GM}{R^2}[/tex]

where

[tex]G=6.67\cdot 10^{-11} m^3 kg^{-1}s^{-2}[/tex] is the gravitational constant

M is the mass of the planet

R is the radius of the planet

For Pluto, we have:

[tex]M=1.30\cdot 10^{22} kg[/tex] is the mass

[tex]R=1,188 km = 1.188\cdot 10^6 m[/tex] is the radius

Substituting, we find its gravitational acceleration:

[tex]g=\frac{(6.67\cdot 10^{-11})(1.30\cdot 10^{22})}{(1.188\cdot 10^6)^2}=0.61 m/s^2[/tex]

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Answer:

1.yes

2.no

3.yes

4.no

5.yes

Answer:

The kinetic energy

Explanation:

The potential energy (P) is the energy that the swing has due to its position, and it can be calculated with the expression

P = m . g . h

where,

m: mass

g: gravity

h: height

The higher is the swing, the more potential energy it has.

On the other hand, the kinetic energy (K) is the energy which a body possesses by virtue of being in motion, and it can be calculated using the expression

K = 1/2 . m . v²

where

v: speed

In B, the swing is virtually still (v = 0), while in A, v is maximum and so is its kinetic energy.

Then, as the swing moves from point B to point A, the kinetic energy increases and the potential energy decreases.

The velocity of the brick is 39.2 m/s downward

Explanation:

The motion of the brick is a free fall motion, since the object is affected only by the force of gravity. Therefore, it has a uniformly accelerated motion towards the ground, with constant acceleration of [tex]g=9.8 m/s^2[/tex].

So, we can find its velocity using the suvat equation:

[tex]v=u+at[/tex]

where

v is the final velocity

u is the initial velocity

a is the acceleration

t is the time

For the brick in this problem (taking downward as positive direction)

u = 0 (it is dropped from rest)

[tex]a=g=9.8 m/s^2[/tex]

Therefore, its velocity after t = 4.0 s is:

[tex]v=0+(9.8)(4.0)=39.2 m/s[/tex]

Downward, because the sign is positive.

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Answer:

The potential energy is related to the mass and height of the object from the ground and to the acceleration due to gravity g, by the expression, PE = m g h. Thus, PE = 65 kg × 8800 m × 9.8 m/s² = 5.6 × 10⁶ Joules. Therefore, the potential energy of the climber will be 5.6 × 10⁶ Joules.

Explanation:

Answer:

In physical changes, substances might change in the form of the matter(the shape) but not in it's chemical composition.

Explanation:

The shape can change as well as the size and look but it's chemical composition does not change........which means a paper folded into a plane remains a paper and doesn't become anything else.

In chemical changes.......a wood burned changes to charcoal in this it's a new substance not the wood we burned.

The making of paper plane is a physical change and burning of wood is a chemical change. Chemical change gives new substance and is irreversible which means u can't get the wood back again. While physical changes don't give new substances and the plane can again be unfolded into a sheet of paper.

In physical changes, substances might change in form but not in chemical composition.

A physical change is a type of change in which the physical form of the substance is changed but not the chemical composition.

These physical changes affect the form of the chemical substance, but not the chemical composition.

Examples of physical changes;

Thus, we can conclude that in physical changes, substances might change in form but not in chemical composition.

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Answer:

3/10

Explanation:

4/5(2)

-1/2(5)

8/10-5/10

3/10

Answer:

I believe its  x = 22

Answer: This is a single displacement reaction and the products are zinc chloride and hydrogen gas.

Explanation:

Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.

[tex]AB+C\rightarrow CB+A[/tex]

Element C is more reactive than element A.

Double displacement reaction is defined as the reaction in which exchange of ions takes place.

[tex]AB+CD\rightarrow CB+AD[/tex]

Synthesis reaction is defined as the reaction in which smaller substances combine in their elemental state to form a larger substance.

[tex]A+B\rightarrow AB[/tex]

Decomposition reaction is defined as the reaction in which a large substance breaks down into smaller substances.

[tex]AB\rightarrow A+B[/tex]

For the given chemical reaction:

[tex]Zn(s)+2HCl(aq.)\rightarrow ZnCl_2(aq.)+H_2(g)[/tex]

The reaction is considered as single displacement reaction.

By Stoichiometry of the reaction:

1 mole of zinc metal reacts with 2 moles of hydrochloric acid to produce 1 mole of zinc chloride and 1 mole of hydrogen gas.

Hence, this is a single displacement reaction and the products are zinc chloride and hydrogen gas.

Answer:

x = 3/4 or x = ((-1)^(1/3) (127 - 18 sqrt(43))^(2/3) - 13 (-1)^(2/3))/(3 (127 - 18 sqrt(43))^(1/3)) - 4/3 or x = 1/3 (13 (-1/(127 - 18 sqrt(43)))^(1/3) - (-1)^(1/3) (18 sqrt(43) - 127)^(1/3)) - 4/3 or x = (-(127 - 18 sqrt(43))^(2/3) - 13)/(3 (127 - 18 sqrt(43))^(1/3)) - 4/3

Explanation:

Solve for x over the real numbers:

4 x^4 + 13 x^3 - 8 x^2 + 21 x - 18 = 0

The left hand side factors into a product with two terms:

(4 x - 3) (x^3 + 4 x^2 + x + 6) = 0

Split into two equations:

4 x - 3 = 0 or x^3 + 4 x^2 + x + 6 = 0

Add 3 to both sides:

4 x = 3 or x^3 + 4 x^2 + x + 6 = 0

Divide both sides by 4:

x = 3/4 or x^3 + 4 x^2 + x + 6 = 0

Eliminate the quadratic term by substituting y = x + 4/3:

x = 3/4 or 14/3 + 4 (y - 4/3)^2 + (y - 4/3)^3 + y = 0

Expand out terms of the left hand side:

x = 3/4 or y^3 - (13 y)/3 + 254/27 = 0

Change coordinates by substituting y = z + λ/z, where λ is a constant value that will be determined later:

x = 3/4 or 254/27 - 13/3 (z + λ/z) + (z + λ/z)^3 = 0

Multiply both sides by z^3 and collect in terms of z:

x = 3/4 or z^6 + z^4 (3 λ - 13/3) + (254 z^3)/27 + z^2 (3 λ^2 - (13 λ)/3) + λ^3 = 0

Substitute λ = 13/9 and then u = z^3, yielding a quadratic equation in the variable u:

x = 3/4 or u^2 + (254 u)/27 + 2197/729 = 0

Find the positive solution to the quadratic equation:

x = 3/4 or u = 1/27 (18 sqrt(43) - 127)

Substitute back for u = z^3:

x = 3/4 or z^3 = 1/27 (18 sqrt(43) - 127)

Taking cube roots gives 1/3 (18 sqrt(43) - 127)^(1/3) times the third roots of unity:

x = 3/4 or z = 1/3 (18 sqrt(43) - 127)^(1/3) or z = -1/3 (-1)^(1/3) (18 sqrt(43) - 127)^(1/3) or z = 1/3 (-1)^(2/3) (18 sqrt(43) - 127)^(1/3)

Substitute each value of z into y = z + 13/(9 z):

x = 3/4 or y = 1/3 (18 sqrt(43) - 127)^(1/3) - (13 (-1)^(2/3))/(3 (127 - 18 sqrt(43))^(1/3)) or y = 13/3 ((-1)/(127 - 18 sqrt(43)))^(1/3) - 1/3 (-1)^(1/3) (18 sqrt(43) - 127)^(1/3) or y = 1/3 (-1)^(2/3) (18 sqrt(43) - 127)^(1/3) - 13/(3 (127 - 18 sqrt(43))^(1/3))

Bring each solution to a common denominator and simplify:

x = 3/4 or y = ((-1)^(1/3) (127 - 18 sqrt(43))^(2/3) - 13 (-1)^(2/3))/(3 (127 - 18 sqrt(43))^(1/3)) or y = 1/3 (13 ((-1)/(127 - 18 sqrt(43)))^(1/3) - (-1)^(1/3) (18 sqrt(43) - 127)^(1/3)) or y = (-(127 - 18 sqrt(43))^(2/3) - 13)/(3 (127 - 18 sqrt(43))^(1/3))

Substitute back for x = y - 4/3:

Answer: x = 3/4 or x = ((-1)^(1/3) (127 - 18 sqrt(43))^(2/3) - 13 (-1)^(2/3))/(3 (127 - 18 sqrt(43))^(1/3)) - 4/3 or x = 1/3 (13 (-1/(127 - 18 sqrt(43)))^(1/3) - (-1)^(1/3) (18 sqrt(43) - 127)^(1/3)) - 4/3 or x = (-(127 - 18 sqrt(43))^(2/3) - 13)/(3 (127 - 18 sqrt(43))^(1/3)) - 4/3

Answer:

-58 i think

Explanation:

-16 - 39 + 16 - 21x = 18 divid 2 -3

-16 - 55 - 39x divided by 2 - 3

-110 divided by 2 - 3

-55 - 3 = -58

Answer: Clouds are evaporated sea water. You should be asking "Why does the gravity on Earth pull us down and not evaporated water.

Explanation:

Answer:

Because of their mass

Explanation:

Clouds are made of water right ? so you are asking why they don't fall down if air is lighter than water .

The two biggest reasons the clouds stay in the sky are

1. Small Drops

2. Wind

Small drops of water fall more slowly than big drops, as the drops of the clouds fall thought the air, the air pushes back to them, because Small drops has less mass than large drops, clouds can only contain small drops of water.

Answer:

Not combustion

Explanation:

I just took a test and got it wrong

The answer is Decomposition

Thank god the answer was removed

I got it correct

Answer:

The Normal and Gravitational Force

Explanation:

The normal force pushes up and is between the ground and the scale. The gravitational force is the force exerted on the ground.

The frictional force is 218.6 N

Explanation:

The block in the problem is at rest along the inclined surface: this means that the net force acting along the direction parallel to the incline must be zero.

There are two forces acting along this direction:

- The component of the weight parallel to the incline, downward along the plane, of magnitude

[tex]mg sin \theta[/tex]

where

m = 46 kg is the mass

[tex]g=9.8 m/s^2[/tex] is the acceleration of gravity

[tex]\theta=29^{\circ}[/tex] is the angle of the incline

- The (static) frictional force, acting upward, of magnitude [tex]F_f[/tex]

Since the block is in equilibrium, we can write

[tex]mg sin \theta - F_f = 0[/tex]

And substituting, we find the force of friction:

[tex]F_f = mg sin \theta = (46)(9.8)(sin 29^{\circ})=218.6 N[/tex]

Learn more about frictional force along an inclined plane:

brainly.com/question/5884009

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Answer: d

Explanation: Unscrew one light, if the others remain on it is a parallel circuit.

The force exerted on the box is 56 N

Explanation:

The work done by a force on an object is given by

[tex]W=Fd cos \theta[/tex]

where

F is the magnitude of the force

d is the displacement of the object

[tex]\theta[/tex] is the angle between the direction of the force and of the displacement

For the box in this problem, we have:

W = 2240 J is the work done

d = 40 m is the displacement of the box

Assuming that the  force is parallel to the displacement, [tex]\theta=0[/tex]

Solving the equation for F, we find the force exerted on the box:

[tex]F=\frac{W}{d cos \theta}=\frac{2240}{(40)(cos 0)}=56 N[/tex]

Learn more about work:

brainly.com/question/6763771

brainly.com/question/6443626

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Answer:

A.28.52

B.3.52

C.35.55

D.10.55

just guessed and got it right lol

Answer:

A.28.52,   B.3.52,   C.35.55,  D.10.55

Explanation: