what is the difference between work and energy? Has any energy been spent if we pass a subject ?

Answer 1

Energy and work are interrelated.

Energy is the capacity or power to do work. For example the energy required to move a train, or heat water. Energy can be gained or released. Heat energy is gained by water being made to boil. Potential energy is released by an object falling due to gravity.

One definition of work is the energy applied to make an object move a certain distance. So work is done by applying energy to make the train move 100 miles. Another definition would be the work carried out by heating a fixed volume of water to boiling.

Yes, energy has been spent if you pass a subject; you will also have done a lot of work!

Answer 2

There is no difference between 'work' and 'energy' (they're both measured in Joules). The difference is that energy is something which can be intrinsically contained in an object (potential energy, or kinetic energy, or chemical energy, or any of many other types) while work is a measure of energy used to change the energy state of another object or system. For example, if we exert 10 Newtons of force (assuming no friction or other forms of energy loss) on a 1 kg object over a distance of 10 meters, we have expended 100 Joules of energy (done 100 J of 'work') and, as a result, the object now contains 100 J of kinetic energy.

Doug

Answer 3

Energy is expended in doing work and work is done when energy is used.
Passing an exam used up both mental and physical energy by reading questions, the use of thought processes and writing the answers....All of this causes a fair bit of tension. This is why you feel 'drained' of energy when it's all over.

Answer 4

Energy is the capcity of the body to do work just as wealth of a person is his capacity to spend. It is the property of the body.

When body A does work on body B, A loses energy to the extent it does work and B gains that energy. Thus work is energy in transfer.

When a wealthy person donates money to a poor person, his wealth reduces by the amount of donation and the poor person's wealth increases by the same amount. Money so transferred is like work done and change in wealth is like change in energy. Donation is like wealth in transfer.