You wish to lift a 400 lb car engine a vertical distance of 3 ft using a strong rope. Unfortunately, your hand crank winch can only generate 100 lb of tension in your rope. In order to overcome this obstacle, you use a multiple pulley system (block and tackle) to lift the engine.

What is the mechanical advantage of this system?

The change in gravitational potential energy of the book is 9.81 J.

The change in gravitational potential energy is calculated as follows:

ΔGPE = m * g * Δh

where:

In this case, the mass of the book is 2 kg, the acceleration due to gravity is 9.81 m/s², and the change in height is 0.5 m (2 m - 1.5 m).

Therefore, the change in gravitational potential energy is:

ΔGPE = 2 kg * 9.81 m/s² * 0.5 m = 9.81 J

Learn more about potential energy:

https://brainly.com/question/21175118

#SPJ3

Answer:

The magnitude of change in momentum of the ball is [tex]97.5 m[/tex] and impulse is also [tex]97.5 m[/tex]

Explanation:

Given:

Velocity of a pitched ball [tex]v _{i} = 47[/tex] [tex]\frac{m}{s}[/tex]

Velocity of ball after impact [tex]v_{f} = -50.5[/tex] [tex]\frac{m}{s}[/tex]

From the formula of change in momentum,

  [tex]\Delta P = m (v_{f} -v_{i} )[/tex]

Here mass is not given in question,

Mass of ball is [tex]m[/tex]

Change in momentum is given by,

[tex]\Delta P = m (-50.5 -47)[/tex]

[tex]\Delta P = -97.5 m[/tex]

Magnitude of change in momentum is

[tex]\Delta P = 97.5 m[/tex]

And impulse is given by

 [tex]J = \Delta P[/tex]

[tex]J = -97.5 m[/tex]

So impulse and

Therefore, the magnitude of change in momentum of the ball is [tex]97.5 m[/tex] and impulse is also [tex]-97.5 m[/tex]

The energy transferred out of the system as heat is 3950 J, or in scientific notation, [tex]\rm \( 3.95 \times 10^3 \, \text{J} \)[/tex]

The amount of energy q required to change the temperature of a substance can be calculated using the formula:

[tex]\rm \[ q = m \cdot C \cdot \Delta T \][/tex]

Where:

m is the mass of the substance

C is the specific heat capacity of the substance

[tex]\rm\( \Delta T \)[/tex] is the change in temperature

Given that the change in temperature is from the system's current temperature to [tex]\( 0^\circ \text{C} \)[/tex], which is -T in Kelvin, and the specific heat capacity C is typically given in [tex]\rm \( \text{J/g}^\circ \text{C} \)[/tex], we can express the formula as:

[tex]\rm \[ q = m \cdot C \cdot (-T) \][/tex]

Given that the energy is to be expressed in joules, we need to use the SI unit for mass (kilograms) and convert the specific heat capacity to [tex]\rm \( \text{J/kg}^\circ \text{C} \)[/tex]

The conversion factor from [tex]\rm \( \text{J/g}^\circ \text{C} \)[/tex] to [tex]\( \text{J/kg}^\circ \text{C} \)[/tex] is 1000 since [tex]\( 1 \, \text{g} = 0.001 \, \text{kg} \)[/tex]:

[tex]\rm \[ C_{\text{SI}} = C_{\text{g}} \cdot 1000 \][/tex]

Now, we can use the formula to calculate q.

Given:

m (mass of the substance) = [tex]\rm \( 4.70 \, \text{kg} \)[/tex] (assuming mass)

C (specific heat capacity) = [tex]\rm \( 4.18 \, \text{J/kg}^\circ \text{C} \)[/tex]

T (temperature change) = [tex]\rm \( 0^\circ \text{C} - 20^\circ \text{C} = -20^\circ \text{C} \)[/tex]

Substitute the values:

[tex]\rm \[ q = (4.70 \, \text{kg}) \cdot (4.18 \, \text{J/kg}^\circ \text{C}) \cdot (-20^\circ \text{C}) \]\\\\rm q = -3949.6 \, \text{J} \][/tex]

Since the answer is expected in kilojoules (kJ), convert the value from joules to kilojoules:

[tex]\rm \[ q = -3949.6 \, \text{J} \\= -3.9496 \, \text{kJ} \][/tex]

Now, express the result with the correct number of significant figures:

[tex]\rm \[ q = -3.95 \, \text{kJ} \][/tex]

Since the question asks for the energy transferred out of the system as heat, take the absolute value:

[tex]\rm \[ q_{\text{abs}} = 3.95 \, \text{kJ} \\= 3950 \, \text{J} \][/tex]

Therefore, the energy transferred out of the system as heat is 3950 J, or in scientific notation, [tex]\rm \( 3.95 \times 10^3 \, \text{J} \)[/tex]

Know more about heat capacity:

https://brainly.com/question/13411214

#SPJ12

To calculate the energy transfer in joules, we need the specific heat capacity of the substance, its mass, and the initial temperature. The formula for this is q = mcΔT. Without these values, we cannot provide a specific numerical answer.

To calculate how much energy needs to be transferred out of the system as heat in order to lower its temperature to 0°C, you would need more information. A key factor of this calculation is the specific heat capacity of the substance in the system, as well as its mass. The formula for heat transfer is q = mcΔT, where m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature. Without the values of m and c as well as the initial temperature, it is not possible to provide a numerical answer in joules.

https://brainly.com/question/32491696

#SPJ3

Answer:

The second one.

Explanation:

The relationship between the electric current and the rate at which a magnet is turning inside an electric generator is linear in nature.

A dynamo is an electric machine that converts mechanical energy into electrical energy. Steam turbines, gas turbines, and wind turbines typically supply mechanical energy to electric generators. Electrical generators supply nearly all of the power needed for electric power grids.

An electric motor converts electrical energy to mechanical energy in the opposite direction. Many similarities exist between motors and generators. However, in this article, we will concentrate primarily on electric generators and how they convert mechanical energy to electrical energy.

Hence,  the relationship between the electric current and the rate at which a magnet is turning inside an electric generator is linear in nature.

Learn more about electric generator here:

https://brainly.com/question/13397492

#SPJ6

Answer:

Yellow, green, polka dot and white jerseys

Explanation:

Tour de France is the biggest bicycle race in the world held at France over a period of 23 days. At the end of each day of racing they give to the certain riders FOUR different colored jerseys:

At the end of the competition, the total points are counted and the different jerseys are given to the overall winners.

Answer:

the answer is ture

Explanation:

because the energy substances must absorb in order to change from liquid to gas

The process of removing heat from a place where it is not wanted and transferring that heat to a place where it makes little or no difference is known as B) refrigeration.

The evaporator in a refrigeration device must be chillier than the refrigerated space for the purpose to take in heat. The boiling factor of a refrigerant ought to be low sufficient at atmospheric strain to preserve the machine stress above 0 PSIG when working at low temperatures.

The evaporator can be thought of as a “warmness sponge.” Vapor is more dense than liquid and, because the liquid refrigerant boils, it has a tendency to sink. The handiest area wherein the refrigerant vapor is superheated is within the evaporator.

Learn more about violations here: https://brainly.com/question/16055406

#SPJ2

Answer:

Boyle's Law

Explanation:

Robert Boyle in his experiment explained the relationship between the volume and the pressure of a gas. In his experiments, he discovered that the volume of a gas is inversely proportional to the pressure at constant temperature. This implies that as the volume of the gas increase, the pressure decreases and as the volume of the gas decrease, the pressure will increase.

Now applying this concenpt to the the plunger of a bicycle pump, you will discover that as the pressure of in the plunger increase, the volume of air inside the chamber is decreasing as it is send out to pump the flat tyre. This clearly indicates inverse proportionality between pressure and volume as explained by Boyle's law.

Therefore, the plunger of a bicycle pump clearly indicates Boyle's law in action.

The operation of a bicycle pump illustrates Boyle's Law. This law states that in a closed system at constant temperature, the volume and pressure of a gas are inversely proportional - as one increases, the other decreases.

The situation you described is an application of Boyle's Law, a concept in physics. Boyle's Law states that the pressure and volume of a gas have an inverse relationship when held at a constant temperature. This means that as the volume of gas decreases, like when you push down the plunger of a bicycle pump, the pressure increases.

When the plunger is pushed down, the volume inside the pump decreases, thereby increasing the pressure. This high-pressure air then moves from an area of high pressure (inside the pump) to an area of low pressure (the flat tire), resulting in air being pumped into the tire.

A practical example aiding understanding is a deflated tire. As we start pumping air into it, its volume first increases with not much increase in pressure. However, once the tire is filled to a point where the walls resist further expansion, pressure increases as more air is pumped in. Therefore, Boyle's Law explains the mechanics of a bicycle pump and similar systems pretty well.

https://brainly.com/question/21184611

#SPJ3

Answer:

Fa==kx

ma=-kx

(3.2)(9.8)=-k(0.12)

k=27 N/M

The spring constant is 27 N/M.

A force is defined as an effect that can change the motion of an object so that an object with mass can change its velocity, i.e., accelerate. Force can also be described simply as a push or pull. A force has both magnitude and direction which makes it a vector quantity.

Force is expressed as Mass times acceleration, i.e. F=ma. The SI unit of force is Newton (N).

F = -kx.

This proportional constant k is called the spring constant which is a measure of the spring's stiffness.

So, when we put both the equation together, we get

ma = -kx

Given, (3.2)(9.8)=-k(0.12)

k=27 N/M

Thus, the spring constant is 27 N/M.

Learn more about Force, here:

https://brainly.com/question/13191643

#SPJ3

Answer:

Red

Explanation:

Red is a colour which has the lowest frequency. Violet has the highest frequency. Frequency has a direct relationship with energy. This means the higher the frequency, the higher the energy. Red has the lowest energy of all the colors too.

The frequency and Energy has an inverse relationship with the wavelength.

However Red has the longest wavelength of about 620 - 780 nanometer.

Answer:

This is as a result that about the central axis a collapsed hollow cone is equivalent to a uniform disc

Explanation:

The integration of the differential mass of the hollow right circular cone yields

[tex]I=\int\limits dmr^2 = \int\limits^a_b {\frac{2Mxr^2}{R^2 +H^2} } \, dx = \frac{2MR^2dx}{(R^2 +H^2)^2} \frac{(R^2 +H^2)^2}{4} = \frac{1}{2}MR^2[/tex]

and for a uniform disc

I = 1/2πρtr⁴ = 1/2Mr².

Final answer:

Both a uniform disc and a hollow right circular cone have the same formula for their moment of inertia when rotating about the central axis because their shapes and mass distributions result in similar rotational behavior.

Explanation:

Both a uniform disc and a hollow right circular cone have the same formula for their moment of inertia when rotating about the central axis because their shapes and distributions of mass result in similar rotational behavior.

The moment of inertia depends on the distribution of mass around an axis of rotation. In both objects, the mass is distributed symmetrically about the central axis, resulting in similar moment of inertia values.

For a uniform disc, the moment of inertia is given by the formula I = 1/2 MR², where M is the mass of the disc and R is its radius. Similarly, for a hollow right circular cone, the moment of inertia is also given by the formula I = 1/2 MR², where M is the mass of the cone and R is the radius of its base.

Explanation:

(a) The given figure is a convex lens.

(b) In this figure, the object is placed between F and optical center of a lens. Convex lens is a converging lens. It converges the beam of light falling on it after reflection. The image is formed on the same side of the lens as the object.

The formed image is enlarged and it is virtual and erect.

(i) Type : virtual

(ii) Orientation : upright

(iii) Size : Enlarged

Answer:

A thin wire has a higher resistance than a thick wire

A short wire has a lower resistance than a long wire

A warm wire has a higher resistance than a cool wire

Explanation:

Here we have the formula for resistance by diameter given as follows

[tex]R = \frac{4 \times \rho \times l}{\pi } \times \frac{1}{d^2}[/tex]

Where:

R = Resistance

ρ = Resistivity of the wire

l = Length of the wire

d = Diameter of the wire

a. Therefore, since resistance is inversely proportional to diameter of the wire, a thin wire

A thin wire produces a higher resistance value than a thicker wire with larger diameter, d

b. Also as resistance is directly proportional to the length of the wire, a long wire has a higher resistance value than a short wire

c. The formula for resistance of a wire with temperature is as follows;

[tex]R_T = R_0 \times [1 + \alpha \times (T - T_{20})][/tex]

Where:

R₀ = Copper resistance at 20°

[tex]R_T[/tex] = Copper resistance at temperature T

T = Copper conductor temperature

T₂₀ = 20°

α = Copper coefficient of resistivity

Therefore, as the temperature increase, the resistance increases.

Answer:

thin wire has  

✔ more

 resistance than a thick wire.

A short wire has  

✔ less

 resistance than a long wire.

A warm wire has  

✔ more

 resistance than a cool wire.

Explanation:

Answer:

4.988kW

Explanation:

According to the question, energy E extracted from the ocean breaker is directly proportional to the intensity I. It can be expressed mathematically as E ∝ I

E = kI where k is the constant of proportionality.

From the formula; k = E/I

This shows that increase in energy extracted will lead to increase in its intensity and vice versa.

If the device produces 10.0 kW of power on a day when the breakers are 1.20 m high

E = 10kW and I = 1.20m

k = 10/1.20

k = 8.33kW/m

To know how much energy E that will be produced when they are 0.600 m high, we will use the same formula

k = E/I where;

k = 8.33kW/m

I = 0.600m

E = kI

E = 8.33 × 0.6

E = 4.998kW

The device will produce energy of 4.998kW when they are 0.600m high.

Answer:

It will produce 2.5 Kw at 0.6m high

Explanation:

We are given;

Initial Power output of device; P_i = 10 Kw

Initial amplitude; A_i = 1.2m

Final Amplitude; A_f = 0.6m

We know that power is directly proportional to energy because

P = Energy(work done)/time taken

Thus; P ∝ E - - - - (eq1)

Now,from the question, we are told that Energy is proportional to the intensity. Thus;

E ∝ I - - - - (eq2)

where I is intensity

Now, from formula of Intensity, which is; I = (1/2)(ρ²•β²•ω²•A²)

We can see that I is directly proportional to square of Amplitude A²

Thus, I ∝ A² - - - - (eq3)

Combining eq 1,2 and 3,we can deduce that;

P ∝ E ∝ I ∝ A²

Thus, P ∝ A²

Now, let's set up the proportion as;

P_i/P_f = A_i²/A_f²

Since we are looking for final power, let us make P_f the subject.

So,

P_f = (P_i•A_f²)/A_i²

Plugging in the relevant values to obtain ;

P_f = (10 x 0.6²)/1.2² = 2.5 Kw

Final answer:

Another term for a Lewis structure diagram is an 'electron-dot diagram,' which represents the valence electrons of an atom as dots around the element's symbol and is used to visualize the bonding and non-bonding electrons in molecules.

Explanation:

Another term for a Lewis structure diagram is an electron-dot diagram. A Lewis structure diagram is a representation that shows the valence electrons of an atom as dots around the symbol of the element. The dots represent the number of valence electrons present in the atom and are arranged around the chemical symbol in a specific manner with a maximum of two dots on one side. For instance, the Lewis diagram for hydrogen would consist of the symbol 'H' with one dot next to it, representing its single valence electron.

The Lewis diagram is also referred to as a Lewis dot diagram and is used to visualize the bonding between atoms as well as non-bonding valence electrons. When atoms bond, the shared electrons are represented by lines, and lone pairs are depicted by dots surrounding the atoms. These diagrams help in predicting the shape of molecules and the arrangement of atoms.

Answer: slipping on a patch of ice (A)

Explanation: there is direct contact when you slip on a patch of ice: your body, and the ice. all of the other answers are either non contact, or it is not solid to solid (wind, water). hope that makes sense :)

Kepler's Third Law helps calculate the period of satellites orbiting Earth based on their radius, aiding in various applications.

Kepler's Third Law: The period of an orbiting object is related to the radius of its orbit. Using the formula n²a³ = GM (where n is the mean motion, a is the semi-major axis, and GM is the product of the gravitational constant and the Earth's mass), we can calculate the period of the satellite's circular orbit.

Calculations: For a satellite at an altitude of 20,200 km above Earth's surface (a = 26,578 km), with GM = 3.986005 x 10¹⁴ m³/s², the period T comes out to be 43,122 seconds.

Application: Understanding Kepler's laws helps in determining crucial parameters for artificial satellites orbiting Earth, aiding in satellite communication, weather observation, and other scientific endeavors.

Answer: Option (b) is the correct answer.

Explanation:

Physical equilibrium is defined as a system in which there will occur no change in the physical state of substance. For example, at zero degree celsius water is present in both liquid and solid state as follows.

      [tex]H_{2}O(l) \rightleftharpoons H_{2}O(s)[/tex]

For a system to be present in physical equilibrium is as follows.

The system must be a closed system.

It should be dynamic in nature.

There will occur no change in measurable property along with change in time.

Thus, we can conclude that ice floats in water at [tex]0^{o}C[/tex] this an example of physical equilibrium because no new substances form when the water molecules change state.

Answer:

Amplitude

Explanation:

The amplitude is maximum height a wave is measured from its rest position.

Answer:

When light travels from air into water, it slows down, causing it to change direction slightly. This change of direction is called refraction. When light enters a more dense substance (higher refractive index), it 'bends' more towards the normal line

Answer:

[tex]2.7\cdot 10^{16} J[/tex]

Explanation:

We can approximate the hurricane as a rotating uniform cylinder, so its energy is the rotational kinetic energy, given by:

[tex]E=\frac{1}{2}I\omega^2[/tex] (1)

where

I is the moment of inertia

[tex]\omega[/tex] is the angular velocity

The moment of inertia of a cylinder rotating about its axis is

[tex]I=\frac{1}{2}MR^2[/tex]

where

M is the mass

R is the radius

So formula (1) can be written as

[tex]E=\frac{1}{2}(\frac{1}{2}MR^2)\omega^2=\frac{1}{4}MR^2\omega^2[/tex] (2)

For an object in rotation, the linear speed at the edge is related to the angular velocity by

[tex]v=\omega R[/tex]

So we can rewrite (2) as

[tex]E=\frac{1}{4}Mv^2[/tex]

where we have:

[tex]v=100 km/h = 27.8 m/s[/tex] is the speed at the edge of the hurricane

We have to calculate the mass of the cylinder. We have:

[tex]R=88 km = 88,000 m[/tex] (radius)

[tex]h=4.4 km = 4400 m[/tex] (height)

So the volume is

[tex]V=\pi R^2 h = \pi (88,000)^2 (4400)=1.07\cdot 10^{14} m^3[/tex]

The density is

[tex]\rho = 1.3 kg/m^3[/tex]

So the mass is

[tex]M=\rho V=(1.3)(1.07\cdot 10^{14})=1.39\cdot 10^{14} kg[/tex]

Therefore, the energy is

[tex]E=\frac{1}{4}(1.39\cdot 10^{14})(27.8)^2=2.7\cdot 10^{16} J[/tex]

Answer:

1.2 A

Explanation:

We are given that

Time, dt=78 ms=[tex]78\times 10^{-3}s[/tex]

[tex]1 ms=10^{-3} s[/tex]

[tex]I_s=4.1mA=4.1\times 10^{-3} A[/tex]

[tex]1 mA=10^{-3}A[/tex]

[tex]R=12\Omega[/tex]

[tex]M=3.2mH=3.2\times 10^{-3} H[/tex]

We have to find the change in the primary current.

[tex]V_s=I_sR=4.1\times 10^{-3}\times 12=49.2\times 10^{-3} V[/tex]

[tex]V_s=M\frac{dI}{dt}[/tex]

[tex]dI=\frac{V_sdt}{M}=\frac{49.2\times 10^{-3}\times 78\times 10^{-3}}{3.2\times 10^{-3}}[/tex]

[tex]dI=1.2 A[/tex]

Answer:

True

Explanation:

This can be done when the output gear is rotating in a counterclockwise direction. The initial direction of the clockwise gear changes when it comes in contact with the counter clockwise rotating gear. This will thus cause the motor to change its direction due to the counter clockwise rotating gear.

Answer:

α = - 0.00148 rad/s^2

Explanation:

Given:-

- The number of blades, n = 7

- The angular speed of blades, w = 0.5 rad/s

- The diameter of golf ball, d = 9.0 x 10^-2 m

- The speed of the ball, v = 0.1 m/s

Find:-

What is the angular acceleration of the windmill?

Solution:-

- We first need to visualize the ball "just passing" through between two successive blades. First we will determine the time taken (t) for the golf-ball to just pass the blades i.e it travelled a distance equal to its diameter (d) with given speed (v) to avoid the blades.

                                      d = v*t

                                      t = d / v

                                      t = 0.09 / 0.1

                                      t = 0.9 s

- It takes t = 0.9s for the golf-ball to just pass the windmill. The same amount of time is taken by the windmill blade to cover an arc distance (s) that is equivalent to the diameter of the ball (d) which is also the width of empty space between two successive blades. The angle (θ) between each blade - denoting empty space can be determined by the seeing that all 7 blades are equally spaced in a circle. So:

                                    θ = 2π / 2*n

                                    θ = π / 7

                                    θ = 0.44879 rads

- So the angular speed of the windmill blade (wf) when the ball passes through can be determined by the formula:

                                    wf = θ / t

                                    wf = 0.44879 / 0.9

                                    wf = 0.49866 rad/s

- Now we will use the first rotational kinematics equation of motion with constant angular acceleration ( α ) as follows:

                                   wf = wi + α*t

- Solve for  ( α ) :

                                    α = ( wf - wi ) / t

- Plug in the values and evaluate ( α ):

                                    α = ( 0.49866 - 0.5 ) / 0.9

                                    α = - 0.00148 rad/s^2

Answer:

Decreasing in altitude and increasing in velocity

Explanation:

The formula for potential energy is:

[tex]E_p = mgh[/tex]

where m is mass, g is constant gravitational energy and h is the potential altitude.

The formula for kinetic energy is:

[tex]E_k = mv^2/2[/tex]

where v is the velocity

Since m,g are constant, to convert from potential energy to kinetic energy, h must decreases while v increases. For example dropping an object from a height.

Answer:

Explanation:

Atractive forces tries to stop objects when they try to escape of the influence of these forces. Examples of this situation are the gravitational force and electric force.

When the object loses speed, its speed is decreasing, that is, its kinetic energy is decreasing, because the kinetic energy depends on speed:

[tex]E_k=\frac{1}{2}mv^2[/tex]

this lost of kinetic energy is equilibrated by the increase of the potential energy generated by the atractive force.

Because of this dynamic between the kinetic energy and the potential energy, the total mechanical energy of the object is conserved.

Answer:

Magnetic compass

Explanation:

A magnetic field is a field that describes the magnetic effect of electric charges in a relative motion.

Magnetic field allows magnets to interact without contact. The principle involved in the function of the compass is that a magnetic field exerts a force on any moving charge and can be measured and detected by this effect.

Answer:

Magnetic compass

Explanation:

The magnetic compass is the most familiar compass type. It functions as a pointer to "magnetic north", the local magnetic meridian, because the magnetized needle at its heart aligns itself with the horizontal component of the Earth's magnetic field

Compasses are mainly used in navigation to find direction on the earth. This works because the Earth itself has a magnetic field which is similar to that of a bar magnet (see the picture below). The compass needle aligns with the Earth's magnetic field direction and points north-south.

Answer:

T

Explanation:

momentum=mass×velocity

The momentum of an object is equal to the mass of the object times the velocity of the object which is true.

In Mechanics, momentum is calculated as the combination of an object's weight and speed. It has both a magnitude and a direction, making it a vector quantity. If an entity has weight m and speed v, then its momentum is given by,

p = mv

Where 'p' is the momentum, 'm' is the mass, and 'v' is the velocity.

Mass in motion is a definition of momentum. All things have mass, thus when something moves, it has momentum because its mass is in motion. The amount of momentum an object possesses depends on two factors: how much and how quickly the material is moving.

It is correct to say that an object's momentum is equal to its mass times its velocity.

More about the momentum link is given below.

https://brainly.com/question/4956182

#SPJ6

If we do the simple equation of 4,000J subtracted by 2,500J  we can easily see that the energy that wasn't useful or wasted is 1,500J

Answer:

4000J transfer and 2500J stored which means you have an energy produce power equals to 6500J. Therefore take 6500J and subtract it with 4000J transfer and there you left with 2500J. so the question is, how much energy is wasted? about 4000 of your energy is been transfer which means it moves out of the original source.

Explanation: