Question

5. A constant force of 100N acts for 5s on a body of mass 10 kg, initially at rest. Find (ii) the final K.E (i) the average power of the force?​

Answer 1

Answer:

As

Initial velocity = 0 m/s

Time = 5 sec

Acceleration = F/m = 100/10 = 10 m/s²

Final velocity = Initial velocity + (Acceleration × time)

v = 0 + 10(5)

 = 50 m/s

So

i) Final KE = 1/2 × m × v²

              = 12500 J

              = 12.5 KJ

ii) Average power = F(v+u)/2

                               = 100 × 25

                               = 2500 watts.