Question

A 125 W motor accelerates a block along a level, frictionless surface at an average speed of 5.0

Answer 1

Answer:

25N

Explanation:

Given parameters:

Power of the motor = 125W

Average speed  = 5m/s

Unknown:

Force supplied to the motor = ?

Solution:

 Work done is the force applied to move a body through a particular distance;

         Work done  = Force x distance

Also,

        Work done  = Power x time

 

So;

             Force x distance = Power  x time

  since force is the unknown;

            Force  = $\frac{Power x time}{distance}$

         Speed  = $\frac{distance }{time}$

             Force  = $\frac{Power}{speed}$

Now solve;

                Force  = $\frac{125}{5}$    = 25N