Q.

A particle moves with a velocity (5i^-3j^+6k^)ms-1 horizontally under the action of a constant force (10i^+10j^+20k^)N. The instantaneous power supplied to the particle is            [2023]

1 200 W  
2 Zero  
3 100 W  
4 140 W  

Ans.

(4)

Power is scalar product of torque times velocity.

P=F·v ; P=(10i^+10j^+20k^)·(5i^-3j^+6k^)

P=50-30+120,  P=140W