Question

A ball of mass 2kg moves with speed 10m/s and it strikes normally with a wall and reflected back

normally with speed of 5m/s , if it’s time of contact with wall is 0.2 sec then find magnitude of change in

momentum and force exerted by ball on the wall.​

Answer 1

m=2kg,u=(10i)m/s,v=(-5i)m/s,t=0.2s

acceleration=v-u/t

-5i-10i/0.2=-15i/0.2=-75m/s²

a=-75m/s²

momentum=mv-mu=-10i-20i=-30i

magnitude=√(-30)²=-20Ns

F=MA=0.2×-75=-15N