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Power due to a force actoing on a block ...

Power due to a force actoing on a block varies with time `t` as shown in figure. Then angle between force acting on the block and its velocity is `:-`

A

Obtuse at `t=1s`

B

`90^(@)` at `t=3s`

C

Acute at `t=7s`

D

Both the stones reach the bottom at different times and with different speeds.

Text Solution

Verified by Experts

The correct Answer is:
D
Power, `P=vec(F).vec(v)` so
`P` positive `rArrthetalt90^(@)`, `P` negative `rArrthetagt90^(@)`
and `P` zero `rArrtheta=90^(@)`
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