Question

A body of 5kg initially at rest is subjected to a force of 20n. calculate the kinetic energy acquired by the body at the end of 10 sec.

Answer 1

we know that-
f=ma or a=f/m
a=20/5=4m/s sq
now body is at rest so u=0
from motion eq 1)
v=u+at
= 0+4×20
v=80m/s
now kinetic energy=1/2mv sq
1/2×5×80×80
40×400=16000 J ans