Question

a body of mass 5 kg initially at rest is subjected to force of 20 Newton what is the kinetic energy acquired by the body at the end of 10th

Answer 1

Force = mass × acceleration

A= F/m

a= 4 m/s ².

We know that,

K.e = 1/2 mv²

To find v:-

V= u+at  

V= 0+40  

V= 40 m/s.

K.E = 1/2 ×5×40×40

K.E =4000 J

Answer 2

formula for kinetic energy
1/2mv^2
mass given
we need to find velocity of body
according to question initial velocity is zero
we know force= m.a.
20=5×v-u/t
here time is 10 sec. so
20=5×v-0/10

4=v/10
v=40m/sec
now
k.e.=1/2×5×40×40
1/2×8000
k.e.=4000J
thats your answer