A person-1 stands on an elevator moving with an initial velocity of 'v' & upward acceleration 'a'. Another person-2 of the same mass m as person-1 is standing on the same elevator. The work done by the lift on the person-1 as observed by person-2 in time 't' is:
1.
2.
3. 0
4.
A block of mass m is placed in an elevator moving down with an acceleration . The work done by the normal reaction on the block as the elevator moves down through a height h is:
1.
2.
3.
4.
In the diagram shown, force F acts on the free end of the string. If the weight W moves up slowly by distance h, then work done on the weight by the string holding it will be: (Pulley and string are ideal)
1. Fh
2. 2Fh
3.
4. 4Fh
The position-time graph of a particle of mass 2 kg is shown in the figure. Total work done on the particle from t = 0 to t = 4s is:
1. | 8 J | 2. | 4 J |
3. | 0 J | 4. | Can't be determined |