A force of 100N acts on an object of mass 10kg for 9seconds. If the object was initially moving with the speed of 10m/s, calculate the initial and final kinetic energy of the object.By what factor does the kinetic energy increase?

Asked by rajinderkaur1528 | 8th Feb, 2019, 03:28: PM

Expert Answer:

F = 100 N, m = 10 kg, t = 9 s, u = 10 m/s, Initial kinetic energy - K.E.i = ?, Final kinetic energy K.E.f = ? 
 
u = 10 m/s,
Thus, K.E.i = 1/2 × m × u2 = 1/2 × 10 × 102 = 500 J 
 
F = m x a
 
a = F/m = 100/10 = 10 m/s2 
 
v = u + at 
v = 10 + (10) x 9
v = 100 m/s 
 
K.E.f = 1/2 × m × v2 = 50000 J
 
Factor by which the kinetic energy increases,
 
fraction numerator K. E subscript i over denominator K. E subscript f end fraction equals space 50000 over 500 space equals space 100

Answered by Shiwani Sawant | 8th Feb, 2019, 05:10: PM