explain the concept of maximum work or give condition for maximum work
Answers
HELLO THERE!
Work is said to be done if a body is displaced along the direction of the force applied.
The last line is very important. For maximum positive work to be done, the displacement should always be in the direction of the force.
For example, if a porter is walking forward on a platform with a load on his head, then he is doing no work. This is because, he is applying a force downwards to hold the load, but displacement is in a forward direction.
For maximum work to be done, the displacement should always be in the direction of force applied. If displacement takes place at an angle from the Force, then we take the component of force along the line of displacement (F cos θ), the base component of the force. If there is any existence of angle (θ), then the work done won't be maximum.
If the angle between force and displacement will be zero (θ = 0), then:
Work = Fcosθ x S
= F cos 0° x S
= FS
This is the maximum work done, when the direction of displacement is equal to the direction of force (as angle between them is zero).
Answer: to understand the concept of maximum work letters considered following cases:
1) when opposing force is zero that is pext = 0 then w = 0 as it expansion in vaccum
2) when opposing force is a less that is pext is very small then pgus work done is less
3) when opposing force is less by small quantity then driving force then amount of work done is large that is maximum this is the condition of reversible process therefore when the process is reversible work done is more
4) according to first law of thermodynamics q = Δu + w if the process is isothermal Δu = 0
Whenever whatever is the amount of heat given to the system it is utilised in doing work hence if the process is isothermal work done is more thus if the process is isothermal and reversible the amount of work done is a maximum called wmas
Explanation: