Question

A force acts on a rest body of mass 2kg for 5 seconds and then force ceases to act and the body moves 80m during 4 seconds .find how much force wor applied on the body

Answer 1

Here,

Mass, m = 10 kg

Let F be the force that acts for t = 10 s.

So, acceleration is, a = F/m

Using, v = u + at

=> v = 0 + 10a  [considering the body starts from rest]

After that 10 s, the force ceases and the body moves with velocity v. In 5 s it covers a distance of 50 m.

So,

S = vt = 50

=> (10a)(5) = 50

=> a = 1 m/s2

Now, F = ma = (10)(1) = 10 N