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

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  =

         Speed  =

             Force  =

Now solve;

                Force  =    = 25N

it doesn't. it was imagined up in the middle ages.

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