A particle of mass 120g moving at speed of 750cm/s is acted upon by a variable forrenpposite to its direction of motion as shown in figure. If the velocity of the particle becomes 250cm/s along the direction of force, fund the value of time't' for which force acted.

Explanation

Area of Ft graph = Impulse = Change in momentum

`1/2(t+6) xx 10^(-2) xx 10`
`=120 xx 10^(-3) (7.5 + 2.5)`
`therefore t= 18 s`