Question

A body of mass 5kg is moving with a momentum of 10kgm/sec. A force of 0.2n acts on it in the direction of motion of body for 10sec. The increase in kinetic energy?

Answer 1

Answer:

Given,

HD 4G4 196%

Physics 5 points

mass(m) = 5 kg momentum(p) = mass velocity = 10 kgm/s force(f) = 0.2 N time of force(t) = 10 sec.

Solution,

p= m*v = 10 kgm/s (5 kg)*v = 10 kgm/s v = (10kgm/s)/5kg = 2m/s hence, initial velocity =2m/s (since it was already moving.)

f=ma

0.2N=(5kg)*a a= (0.2N)/(5kg) a= 0.04 m/s

a= (final velocity-initial velocity)/change in time a= Av/At = (v-u)/At

0.04 m/s2 = (v-2)/10 sec V= (0.04*10)+2 v = 2.4 m/s

change in kinetic energy = (mv/2) - (mu?/2) = (m/2) (v2-u) = (5/2) (2.4 - 2) = 4.4 joule.