How do I find the amount heat energy generated from pushing a crate?

[pokeefer]

Homework Statement

A force of 120N pushes a crate of mass 15 kg along the ground at a constant speed of 3.2 m/s for a distance of 6.2m. What amount of heat energy was generated during this time?

Homework Equations

W = Fd
KE + PE = KE ' + PE '

The Attempt at a Solution

I don't know if the law of conservation of energy still applies somehow.

 

[kjohnson]

Homework Statement

A force of 120N pushes a crate of mass 15 kg along the ground at a constant speed of

If its pushed at a constant speed what other force must be acting on the crate?

 

[pokeefer]

If its pushed at a constant speed what other force must be acting on the crate?

I'm guessing the force of friction.

But would I be able to solve for heat energy by:

Work = Change in kinetic energy

Then finding the initial kinetic energy and then

Ke Final = Work - Ke initial

Ke Final = Fd - 1/2 mv^2

?

 

[kjohnson]

Since friction is not a conservative force that means that energy is being dissipated or lost from the system. So you want to make the assumption that the energy lost because of friction is...

 

[rwisz]

As a scientist, you can use the formula for work (W = Fd) to calculate the amount of work done by the force (120N) on the crate over a distance of 6.2m. This work done is equal to the amount of energy transferred to the crate, which can be converted to heat energy.

However, in this case, since the crate is moving at a constant speed, there is no change in kinetic energy (KE) or potential energy (PE), so the formula KE + PE = KE' + PE' is not applicable.

To find the amount of heat energy generated, you can use the formula for work (W = Fd) and the definition of power (P = W/t) to calculate the power (energy per unit time) exerted on the crate. Then, you can use the specific heat capacity of the crate's material to calculate the amount of heat energy generated.

Alternatively, you can also use the formula for mechanical energy (ME = KE + PE) to calculate the total mechanical energy of the crate before and after the push, and then subtract the two values to find the change in energy, which can be converted to heat energy.

In summary, to find the amount of heat energy generated from pushing a crate, you can use either the formula for work (W = Fd) or the formula for mechanical energy (ME = KE + PE) and then convert the resulting energy to heat energy using the appropriate conversion factor.