Question

Deduce how work done is related to energy when
1 - friction is present
2 when friction is not present

Answer 1

If there is friction, then work done by frictional forces convert
Part of the energy into heat.

If there is no friction, work W = E, energy
Energy is ability to do work, work increases
E.g kinetic energy or potential energy of the object.

Answer 2

Thnax. but if you could elaborate it with mathematical equations plz

Answer 3

If a body is lifted, W = mgh= Change of potential energy

If speed changes, W = 0,5mv^2= change of kinetic energy

If a body has potential energy Ep and it slides down a distance s
And there is friction force F, then work done by friction is W = Fs.

Then final kinetic energy
Ek = Ep - W, because friction takes part of the original
Energy and converts it into heat.

Answer 4

thanx