Question

For how long should a force of 100 N act on a body of 20 kg so that it acquires a velocity of 100 m/s ?

Answer 1

We are going to find acceleration
Force = mass × acceleration        
`100 = 20 xx a`
⇒ `a = 100/20`
⇒ a = 5
Now, putting these values in the equation : 
`v = u + at`
⇒ `100 = 0 + 5 xx t`
⇒ 100 = 5t
⇒ t = 20
So , the required time is 20 s .