All Questions

Tagged with
Filter by
Sorted by
Tagged with
1
vote
3answers
49 views

Work done over a closed loop

Is it true that the work done in the motion of a body over a closed loop is zero for every force in nature?
0
votes
1answer
51 views

Sign of the work done by dissipation forces

I don't understand this passage from the book I'm reading: Physically, it is clear that a system cannot be conservative if friction or other dissipation forces are present, because $\mathbf{F}\...
1
vote
2answers
46 views

Force, work and the apparent disappearance of Mechanical Energy [duplicate]

A man exerts force on a wall of bricks. The man must have consumed the energy he possessed (mechanical energy?) to exert the force. The man sweats and tires himself out but the wall does not move. ...
-1
votes
1answer
521 views

Energy dissipated by friction vs Work done by friction

Is energy dissipated by friction the same as work done by friction where the equation is W(friction) = Ff * d cos theta . However, since work is the transfer of energy and not energy itself then is ...
1
vote
1answer
79 views

Why is there no friction energy?

Can anyone briefly explain to me why is there no term for frictional energy when they often referred to work done by friction instead? Thank you
15
votes
4answers
2k views

What exactly makes a force conservative?

I get that forces can be classified as either conservative or non-conservative, depending on whether the work done in a round trip is zero or non-zero. What property of the force makes it to be, ...
1
vote
3answers
2k views

Work done in thermodynamics [duplicate]

The work done in thermodynamic process is given by the integral of Pdv and also we can write so assuming a quasi static process between two points. But this work is then non dissipative work or work ...
3
votes
3answers
661 views

Dissipation and first law of thermodynamics

Consider the following situation: a certain gas is contained in a well-insulated cylinder with a well-insulated piston head. Now, in this case the piston is not frictionless. In order for the piston ...
0
votes
1answer
53 views

Change of energy into friction?

If I am pushing a car and it does not move, I am doing no mechanical work. However, I am changing the energy that was stored in my cells into heat energy (maybe sound energy if my hand slips off the ...
1
vote
2answers
1k views

Work done against a resistive force

My past year exam paper had a question about work done against the resistive force, where the answer key said it was resistive force * distance. As I understand it, work done is a measure of impact a ...