8. Using a ramp 6 meters long, workers apply an effort force of 1250 N to move a
2000 N (F.) crate onto a platform 2 meters high. What is the efficiency of the
ramp? (Hint: calculate Win & Wout, then efficiency
​

The power is 833.3 W

Explanation:

First of all, we need to calculate the work done in lifting the barbell, which is equal to the change in gravitational potential energy of the barbell:

[tex]W=(mg)h[/tex]

where

mg = 1250 N is the weight of the barbell

h = 2 m is the change in height

Substituting,

[tex]W=(1250)(2)=2500 J[/tex]

Now we can calculate the power, which is equal to the work done per unit time:

[tex]P=\frac{W}{t}[/tex]

where

W = 2500 J is the work done

t = 3 s is the time taken

Substituting,

[tex]P=\frac{2500}{3}=833.3 W[/tex]

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Answer:

Voltage difference causes charge to flow from higher potential to that of a lower potential.

Explanation:

Voltage Difference:

It is work done per unit charge in moving a charge from one point to another point.

V = Voltage difference

W = Work done

Q = Charge

Then,

[tex]V = \frac{W}{Q}[/tex]

unit : Volt or Joule/Coulomb

Flow of charge :

A free positive charge move from a region of higher potential to that of lower potential whereas a free negative charge moves from lower potential region to a higher potential.

Thus, a voltage difference is required for the flow of charge.

Direction of conventional current is from positive terminal to negative terminal.

Direction of electron is from negative to positive.

Voltage difference causes charge to flow from higher potential to that of a lower potential.

This is also known as Voltage difference and it is the difference in electric potential between two points.

V= W/Q

where v is potential difference, w is work done and q is charges.

This allows for charges to flow from higher potential to that of a lower potential.

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The final velocity of the candy is 57.7 m/s

Explanation:

The motion of the candy is a free fall motion, since it is subjected only to the force of gravity, so it is a uniformly accelerated motion and therefore we can use the following suvat equation:

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

where

v is the final velocity

u is the initial velocity

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

s is the vertical displacement

In this problem, we have:

u = 0 (the candy is dropped from rest)

s = 170 m (the vertical displacement is the height of thr monument)

Solving for v, we find the velocity of the candy as it hits the  ground:

[tex]v=\sqrt{u^2+2as}=\sqrt{0+2(9.8)(170)}=57.7 m/s[/tex]

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Answer:Kinetic Energy. Kinetic energy is motion — of waves, molecules, objects, substances, and objects. Chemical Energy is energy stored in the bonds of atoms and molecules.

please give me brainliest...

Answer:

Chemical Energy

Explanation:

Energy is the ability to perform work, it is usually stored in many forms. A body at rest has potential energy, a car moving has kinetic energy while  boiling water posses thermal energy. Energy is usually transformed from one form to another, it cant be destroyed.

Chemical energy is the type of energy that is stored in the bonds of the atom of chemical substances. This is the potential energy that is released when the bonds of molecules are broken. For example, the human digestive system breaks down a molecule of food and release mechanical energy for our day to day activities.

The energy stored in between bonds of atoms is chemical energy that are released  and converted to another form of energy when it is broken down.

Answer:

At the same time.

Explanation:

In the first case ,

intial velocity = 0

displacement = -h

acceleration = -g

Using second equation of motion,

s = ut + .5a[tex]t^{2} \\[/tex]

- h = - 0.5g[tex]t^{2} \\[/tex]

t = [tex]\sqrt{\frac{2h}{g} }[/tex]

In the second case, consider only motion along y axis,

intial velocity = 0 ( all the velocity is along x axis)

displacement = -h ( height is same in both cases)

acceleration = -g

Using second equation of motion,

s = ut + .5a[tex]t^{2} \\[/tex]

- h = - 0.5g[tex]t^{2} \\[/tex]

t = [tex]\sqrt{\frac{2h}{g} }[/tex]

In both cases time is same.

Hence, they will reach the ground simultaneously.

Answer:

The speed of the block after it has moved 3M if the surface in contact have a coefficient of kinetic friction of 0.15​  is 1.7s m/sec

Explanation:

Given:

mass of the block = 6.0 kg

Force with which the block is pulled = 12 N

Kinetic friction \mu= 0.15

Distance travelled  s = 3 m

To Find:

speed of the block after it has moved 3 metres =?

Solution :

W know that the friction formula is

[tex]f_k = \mu m g[/tex]

Substituting the values,

[tex]f_k = (0.15)(6)(10)[/tex]

[tex]f_k= 9 N[/tex]

Now Acceleration is Given by

[tex]a=\frac{F -f_k}{m}[/tex]

[tex]a=\frac{12 - 9}{60}[/tex]

[tex]a=\frac{3}{6}[/tex]

a= 0.5 [tex]m/s^2[/tex]

Initial velocity is u = 0

Also we know that,

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

So the equation becomes

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

[tex]v=\sqrt{2as}[/tex]

Substituting the values,

[tex]v=\sqrt{2as}[/tex]

[tex]v=\sqrt{2(0.5)(3)}[/tex]

[tex]v= \sqrt{3}[/tex]

v= 1.73 m/s

An beta particle is a fast-moving electron.

An alpha particle and a helium nucleus are the same thing . . . a package composed of two protons and two neutrons.

An positron is a particle with the same mass as an electron but a positive charge.

Answer:

Impossible to determine

Explanation:

In other words, no machine can be more than 100% efficient. Machines cannot multiply energy or work input. ... If a machine were 100% efficient then it can't have any energy losses to friction, so no friction can be present. In that case the theoretical and actual mechanical advantages would be equal.

Answer:

R=50 meters

Explanation:

We'll use the Pythagoras's theorem

[tex]R^2=a^2+b^2[/tex]

A right triangle with legs of a=40 m and b=30 m has an hypotenuse of

[tex]R^2=30^2+40^2=900+1600[/tex]

[tex]R=\sqrt{2500} =50[/tex]

[tex]R=50\ meters[/tex]

Answer:

b 50

Explanation:

just did it

Answer:

Mass 1

Explanation:

Take any set of points of the masses:

Let's say the masses in the acceleration 4 m/s (because it represents the points more clearer)

Force = mass × acceleration.

But we need to know the mass if force and acceleration is given.

So,

Mass = Force ÷ acceleration

Now back to the set of points

mass = force ÷ acceleration

For mass 1,

mass = 8 ÷ 4

mass = 2

For mass 2,

mass = 4 ÷ 4

mass = 1

For mass 3,

mass = 2 ÷ 4

mass = 1/2

As you can see from the results, mass 1 definitely has the largest.

Now that you have read through here and think, "we might as well depend on the graph". You are correct but sometimes you should not rely on the graph.

Answer:

Mass 1

Explanation:

I have done the test.

Answer:

S = 108m

Explanation:

According to Second Law of Motion:

S = Vi*t + 0.5*a*t^2

Vi = 21m/s

a = 3m/s^2

t = 4s

Putting all values in Equation

S = 21*4 + 0.5*3*4^2

S = 84 + 24

S = 108m

Answer:

2 m/s

Explanation:

Final answer:

Division and subtraction are not associative operations, meaning that the grouping of numbers can affect the outcome of these operations.

Explanation:

An operation is considered associative if a change in the grouping of the elements does not change the result of the operation. For example, in addition, (a + b) + c = a + (b + c). This means that addition is associative. Similarly, multiplication is associative as well: (a × b) × c = a × (b × c).

Division and subtraction are operations that are not associative. The expression (a - b) - c does not necessarily equal a - (b - c), and similarly, (a / b) / c is not the same as a / (b / c). These operations cannot be regrouped without potentially changing the outcome.

Therefore, the answer to the question is C. division and subtraction are operations that are not associative.

Particle A orbits the nucleus, and Particle B is located in the nucleus.

Explanation:

The atoms consists of three types of particle:

- Proton: it is located in the nucleus of the atom, its mass is approximately [tex]1.67\cdot 10^{-27}kg[/tex], and its charge is [tex]+e=1.6\cdot 10^{-19}C[/tex] (positive charge)

- Neutron: it is also located in the nucleus of the atom, its mass is similar to that of the proton, and it has no electric charge

- Electron: it orbits around the nucleus, it is much lighter than the proton and the neutron (mass: [tex]9.11\cdot 10^{-31}kg[/tex]), and it is negatively charged ([tex]q=-e=-1.6\cdot 10^{-19}C[/tex])

Looking at the definitions above, and since we know that particle A has very little mass in comparison to particle B (so, particle A must be an electron), we can only conclude the following:

Particle A orbits the nucleus, and Particle B is located in the nucleus.

In fact, we cannot determine whether particle B is a proton or a neutron, since we don't know anything about its charge.

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Answer: the correct answer would be Particle A orbits the nucleus, and Particle B is located in the nucleus. I think Particle A represents the electrons while B represents protons and neutrons.

Explanation:

The mass of the water is 41.9 g

Explanation:

When an amount of energy Q is supplied to a sample of substance of mass m, the temperature of the substance increases by [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

In this problem, we have:

Q = 525 J is the amount of heat supplied to the water

[tex]\Delta T = 3^{\circ}C[/tex] is the change in temperature of the water

[tex]C_s = 4.18 J/gC[/tex] is the specific heat capacity of the water

Solving for m, we find the mass of the water:

[tex]m=\frac{Q}{C_s \Delta T}=\frac{525}{(4.18)(3.0)}=41.9 g[/tex]

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Final answer:

Using the specific heat capacity formula, we calculate the mass of water that can have its temperature increased by 3.0° C with the addition of 525 J of heat.

Explanation:

To solve the problem presented, we need to use the concept of specific heat capacity, which is the amount of heat required to raise the temperature of one kilogram of a substance by one degree Celsius. The specific heat capacity of water is commonly accepted as 4,184 J/kg/
°C. We can use the formula q = mcΔT, where q is the heat added (in Joules), m is the mass of the water (in kilograms), c is the specific heat capacity, and ΔT is the change in temperature (in degrees Celsius).

We are given q = 525 J and ΔT = 3.0°C. We need to find the mass m. Rearranging the formula to solve for m, we get m = q / (cΔT). Substituting the given values:

m = 525 J / (4,184 J/kg/
°C
* 3.0°C)

By calculating this, we find the mass of water that can have its temperature raised by 3.0°C with 525 J of heat.

The force of gravity causes a volleyball to accelerate downwards when it rises in the air.

Initially, as the ball rises, gravity slows down its vertical velocity until it comes to a stop at its maximum height and then starts descending back to the ground due to the force of gravity.

D

The exact location of electrons in electron shells of atoms cannot be exactly ascertained. This is why VSPER atomic models represent the position of electrons (s, p, d, & f) using the probability of where they would most be expected to be found.

Explanation:

This is because merely observing electrons changes their behavior. Remember that to observe something one has to shine light on it so it bounces back to the eye. Due to the negligible mass of electrons, mere photons of light will change their direction of movement, spin or other behaviors/properties.

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Answer:

6

8

6

on edge

Explanation:

Answer:  600 kg-m/s

Explanation:

Momentum = mass x velocity

momentum of spaceship 1 = 200 x 2

= 400 kg-m/s

momentum of spaceship 2 = 200 x 2

= 200 kg-m/s

Their combine momentum = 400 + 200 = 600 kg-m/s

The Answer is 600 kg-m/s

Answer:

μ = 0.535

Explanation:

On a level floor, normal force = weight.

N = W

Friction force = normal force × coefficient of friction.

F = Nμ

Substitute:

F = Wμ

83 = 155μ

μ = 0.535

Round as needed.

Answer:

Explanation:

       A object dropped from a plane from a certain height will follow a parabolic trajectory because it has a horizontal velocity equal to plane's velocity.

       So, if supplies are to be dropped from a plane from a height of 160 m, let us calculate the time it takes to reach the ground.

       [tex]H=\frac{1}{2}gt^{2}\\160=\frac{1}{2}\times10\times t^{2}\\t=\sqrt{32}=4\sqrt{2}\text{ }sec[/tex]

       So, in this time, the supply moves a horizontal distance of [tex](4\sqrt{2}\text{ }sec)\times(45\text{ }\frac{m}{sec})=180\sqrt{2}\text{ }m=254.56\text{ }m[/tex].

∴ The supply must be dropped when the plane is 255 m away.

The new gravitation force at the new location is 40 N

Explanation:

The weight of the astronaut is given by the equation

[tex]F=mg[/tex] (1)

where

m is the mass of the astronaut

g is the acceleration of gravity

The acceleration of gravity at a certain distance [tex]r[/tex] from the centre of the Earth is given by

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

where G is the gravitational constant and M is the Earth's mass. So we can rewrite eq.(1) as

[tex]F=\frac{GMm}{r^2}[/tex]

When the astronaut is on the Earth's surface, [tex]r=R[/tex] (where R is the Earth's radius), so his weight is

[tex]F=\frac{GMm}{R^2}=640 N[/tex]

Later, he moves to another location where his distance from the Earth's surface is 3 times the previous distance, so the new distance from the Earth's centre is

[tex]r'=3R+R=4R[/tex]

Therefore, the new weight is

[tex]F'=\frac{GMm}{(4R)^2}=\frac{1}{16}\frac{GMm}{R^2}=\frac{F}{16}[/tex]

Which means that his weight has decreased by a factor 16: therefore, the new weight is

[tex]F'=\frac{640}{16}=40 N[/tex]

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Final answer:

The gravitational force on the astronaut 3 times farther from the Earth's surface than the radius would be 40 N, as at this distance the gravitational force is reduced to 1/16th of its original value.

Explanation:

The question asks: If an astronaut weighs 640 N on the earth's surface, what is the gravitation force between him and the earth if he is 3 times the distance from the Earth's surface? This requires understanding of Newton's law of universal gravitation, which can be expressed as F = G(m1m2)/r², where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between their centers of mass.

As the astronaut moves to a distance 3 times farther from the surface of the Earth, the distance (r) from the center of the Earth becomes 4r, because the initial distance from the surface to the center of the Earth (the radius of the Earth, or 1r) is included. According to the inverse-square law, if the distance increases by a factor of n, the force decreases by a factor of n2. Thus, at 3 times the distance from the surface, or 4 times the radius of the Earth, the gravitational force becomes 1/16th of what it was at the surface.

Therefore, the new gravitational force is 640 N / 16 = 40 N.

1) The ball's speed is 3 m/s

2) The final speed of the raft is 0.6 m/s

3) The collision is inelastic

Explanation:

1)

The momentum of an object is given by

[tex]p=mv[/tex]

where

p is the momentum

m is the mass of the object

v is its velocity

For the ball in this problem we have:

p = 12 kg m/s

m = 4 kg

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

[tex]v=\frac{p}{m}=\frac{12}{4}=3 m/s[/tex]

2)

We can solve this part by applying the law of conservation of momentum: in fact, the total momentum of an isolated system (=no external forces) must be conserved. Therefore we can write:

[tex]p_i = p_f[/tex] (1)

where

[tex]p_i = 0[/tex] is the total initial momentum (the swimmer and the raft are at rest at the beginning)

[tex]p_f = mv + MV[/tex] is the total final momentum, where

m = 75 kg is the mass of the swimmer

M = 500 kg is the mass of the raft

v = 4 m/s is the final velocity of the swimmer

V is the final velocity of the raft

And substituting into (1) we find:

[tex]0=mv+MV\\V=-\frac{mv}{M}=-\frac{(75)(4)}{500}=-0.6 m/s[/tex]

Where the negative sign indicates that the raft moves in the opposite direction to the swimmer: so, the speed of the raft is 0.6 m/s.

3)

In a collision between two objects, if the system is isolated the total momentum of the system is always conserved during the collision. However, this is not true for the total kinetic energy: in fact, due to the presence of internal frictions, part of the kinetic energy can be converted into thermal energy or other forms of energy.

Therefore, there are two types of collision:

- Elastic collision: in an elastic collision, also the total kinetic energy of the objects is conserved

- Inelastic collision: in an inelastic collision, the total kinetic energy is not conserved. The most extreme case is the perfectly inelastic collision, in which the two objects stick together after the collision, and in this case there is the maximum loss of kinetic energy.

Since in this problem the two objects stick together, the collision is inelastic.

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In Physics, a reference direction denotes a clear direction related to motion. Options A, B, and C are valid reference directions, but '2 E' (option D) is not a clear reference direction.

In the context of Physics, a reference direction is an established direction, such as north, south, east, west, up, down, left, or right, used to describe the direction of a vector. These are often used in assessments of motion to delineate the path of an object. In your question, 'A. +', 'B. S', and 'C. down' can be considered as reference directions where '+' denotes a positive direction, 'S' represents South, and 'down' indicates a downward direction. However, 'D. 2 E' does not fit the criteria for a reference direction as '2 E' does not represent an established direction. Instead, it seems like a combination of a numeric value '2' and a directional reference 'E' (possibly East), but as a whole, it is not itself a clear direction.

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Answer:

the mass of the object is 10 kg

Explanation:

In the image attached, we can see the free body diagram and using the newton's second law of movement, we will have one equation with one unknown value (the mass of the object).

where:

m [kg]

a [m/s^2]

F [N] or [kg*m/s^2]

Answer:

10kg

Explanation:

The information we have is:

Force: [tex]F=30N[/tex]

acceleration: [tex]a=3m/s^2[/tex]

What we need to know is the mass of the object. For this we can use Newton's second law:

[tex]F=ma[/tex]

Where F is the Force applied, m is the mass of the object, and a is its acceleration.

from this equation we clear for the mass [tex]m[/tex]:

[tex]m=\frac{F}{a}[/tex]

and we substitute the known values:

[tex]m=\frac{30N}{3m/s^2}=10kg[/tex]

The mass of the object is 10kg

Answer:

The distance the hiker walked is, d = 13 km

The displacement of the hiker is, S = 9.4 km

Explanation:

Given data,

The displacement of towards east, d₁ = 1 km

The displacement of towards north, d₂ = 2 km

The displacement of towards east, d₃ = 4 km

The displacement of towards north, d₄ = 6 km

The total distance the hiker walked

                           d = d₁ + d₂ + d₃ + d₄

                              = 1 + 2 + 4 + 6

                              = 13 km

The distance the hiker walked is, d = 13 km

The resultant displacement of the hiker, S

                                S = √( A² + B² + 2 A B cosФ)

Where,

                         A = d₁ + d₃ = 5 km

                         B = d₂ + d₄ = 8 km

                         Ф = angle between A and B = 90°

Substituting in the displacement equation

                          S = √( 5² + 8²)

                              = 9.4 km

Hence, the displacement of the hiker is, S = 9.4 km

Answer:

gravity

Explanation:

gravity

Answer:

This is because the earth is already going very fast. This means the earth is constantly trying to leave orbit and hurtle off into space like a ball attached to a string would if you spun it around. The only thing keeping that ball from going into your face it the speed.

Explanation:

The gravity is the string.

The earth doesn't really slow down because space offers little resistance.

The angle of incidence in glass is [tex]34.7^{\circ}[/tex]

Explanation:

We can solve this problem by applying Snell's law of refraction, which states that:

[tex]n_1 sin \theta_1 = n_2 sin \theta_2[/tex]

where

[tex]n_1, n_2[/tex] are the index of refraction of the first and second medium, respectively

[tex]\theta_1, \theta_2[/tex] are the angle of incidence and refraction, respectively

In this problem we have:

[tex]n_1 = 1.52[/tex] is the index of refraction of the first medium (glass)

[tex]n_2 = 1.00[/tex] is the index of refraction of the second medium (air)

[tex]\theta_2 =60^{\circ}[/tex] is the angle of refraction in glass

Solving for [tex]\theta_i[/tex], we find the angle of incidence:

[tex]\theta_1 = sin^{-1} (\frac{n_2 sin \theta_2}{n_1})=\sin^{-1}(\frac{(1.00)(sin 60^{\circ})}{1.52})=34.7^{\circ}[/tex]

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Final answer:

Using Snell's Law and the given indices of refraction for crown glass and air, as well as the angle of refraction in air, the angle of incidence within the crown glass is calculated to be approximately 41.14°.

Explanation:

To find the angle of incidence in glass when a ray of light exits the glass into air with a known angle of refraction, we use Snell's Law, which states that n1
*sin(θ1) = n2
*sin(θ2), where n1 and n2 are the refractive indices of the glass and air respectively, and θ1 and θ2 are the angles of incidence and refraction respectively. Given that the refractive index of crown glass is 1.52 (n1 = 1.52) and air is 1.00 (n2 = 1.00), with an angle of refraction of 60° in air (θ2 = 60°), we can rearrange Snell's Law to solve for the angle of incidence (θ1).

First, we plug in our known values:
1.52
*sin(θ1) = 1.00
*sin(60°)

Calculating the sine of 60 degrees and dividing by the refractive index of crown glass gives us the sine of the angle of incidence:

sin(θ1) = (1.00/1.52)
* sin(60°)

sin(θ1) ≈ 0.657

Using the inverse sine function, we find:

θ1 ≈ sin^−1(0.657)

θ1 ≈ 41.14°

Therefore, the angle of incidence in the crown glass is approximately 41.14°.

Answer:

D. 0.29

Explanation:

Answer:

Centripetal force is the force that is necessary to keep an object moving in a curved path and that is directed inward towards the center of rotation.

Explanation:

Definition of centripetal force:

Centripetal force is the force that is necessary to keep an object moving in a curved path and that is directed inward towards the center of rotation.

Example of centripetal force

A string on the end of which a stone is whirled about exerts a centripetal force on the stone.

The diagram is shown below

Where

The centripetal forces acting towards the centre C that is [tex]\vec {AC}[/tex]

and the direction is from A to C.

And the stone is moving in a circular motion with center as C.

Answer:

I think D.

Injured cells stimulate pain, swelling, redness, and heat- which initiates bradykinin-which stimulates the release of histamine- which increases neutrophils and macrophages- leads to phagocytosis of foreign invaders.

Answer:

Injured cells stimulate bradykinin- which initiates the release of histamine- which causes pain, swelling, redness, & heat- increases neutrophils & macrophages- leads to phagocytosis of foreign invaders

Explanation:

Took the test