Question

(a) At a certain instant, a particle-like object is acted on by a force F = (5.0 N) i hat - (2.0 N) j + (8.0 N) k while the object's velocity is v = - (2.0 m/s) i hat + (4.0 m/s) k. What is the instantaneous rate at which the force does work on the object?

Answer 1

Answer:

Power, P = 22 W

Explanation:

It is given that,

Force acting on the object, $F=5i-2j+8k$

Velocity of the object, $v=-2i+4k$  

To Find,

The rate at which the force does work on the object

Solve,

The rate at which the force does work on the object is called its power. Its formula is given by :

$P=\dfrac{W}{t}$

$P=\dfrac{F.d}{t}$

$P=F\times v$

$P=(5i-2j+8k)\times (-2i+4k)$

$P=-10+0+32=22\ W$

So, the force work on the object at the rate of 22 watts