Question

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

m/s. What force is supplied by the motor in the direction of motion??
a. 25 N b. 6.3 x 102 N c. 1.3 x 102 N d. 0.040 N

Answer 1

25N

Step-by-step 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 =
`(Power x time)/(distance)`

Speed =
`(distance )/(time)`

Force =
`(Power)/(speed)`

Now solve;

Force =
`(125)/(5)` = 25N