# Work Equals Potential and Kinetic Energy - Clarification Needed

• moomoocow
In summary, the conversation discusses the relationship between work, potential energy, and kinetic energy. The conclusion is that the change in energy is equal, not the actual values of potential and kinetic energy. The example of a box on a hill with friction is used to illustrate this concept. Additionally, it is mentioned that even on a frictionless surface, there is still potential energy and kinetic energy, but they may not be equal.
moomoocow
hi!

can i say that
when work is done, it is equal to potential energy, which is equal to kinetic energy?

can somebody please correct me if i misunderstood it?

Last edited:
nah u can't say that.basically u can't even say PE is equal to KE its the change that is equal

when work is done energy is converted from one form to the other

the potentail energy may not necssarily equal the kinetic energy... what if there was friction or some other external force?

oo
so its the loss of potential energy which is equal to KE?

moomoocow said:
oo
so its the loss of potential energy which is equal to KE?

this is not always true

think of this:

suppose there was box on top of a hill. And the surface of the hill had friction. Then as the box slides down the hill what can you say about the kinetic energy gained by this box? Is it equal to the potnetial energy lost? Wh or Why not??

suppose u push a box on a frictionless surface, PE wrt the floor will always be zero but there is still some KE

## What is the difference between potential and kinetic energy?

Potential energy is the energy possessed by an object due to its position or configuration, while kinetic energy is the energy possessed by an object due to its motion.

## How is work related to potential and kinetic energy?

Work is the transfer of energy from one form to another, so when work is done on an object, its potential or kinetic energy can change. For example, pushing a swing increases its potential energy, and releasing it increases its kinetic energy.

## Can an object have both potential and kinetic energy at the same time?

Yes, an object can have both potential and kinetic energy at the same time. For example, a rollercoaster at the top of a hill has potential energy due to its height, but also has kinetic energy because it is in motion.

## How is the equation for work related to potential and kinetic energy?

The equation for work (W) is W = F*d, where F is the force applied and d is the distance over which the force is applied. This equation also applies to changes in potential and kinetic energy, as the force applied can change an object's position (potential energy) or speed (kinetic energy).

## Is work always equal to the change in potential and kinetic energy?

In an ideal situation with no energy losses, work is indeed equal to the change in potential and kinetic energy. However, in real-world scenarios, there may be other factors such as friction or air resistance that can affect the amount of work done and the change in energy.

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