Question
A body of mass 1 kg begins to move under the action of a time dependent force F = 
N, where 
are units vectors along X and Y axis. What power will be developed by the force at the time (t)?
-
(2t2 + 4t4) W
-
(2t3 + 3 t4) W
-
(2t3 + 3t5) W
-
(2t + 3t3)W
Solution
C.
(2t3 + 3t5) W
A body of mass 1 kg begins to move under the action of time dependent force,
F = (2t 
+3t2 
) N,
where 
are unit vectors along X and Y axis.
F = ma
Acceleration, a = 
Integrating both sides, we get
Power developed by the force at the time t will be given as,
P = F.v = (2t 
+ 3t2 
).(
)
= (2t. t2 + 3t2.t3)
P = (2t3 + 3t5) W
