A riding ball of mass `m` strikes a rigid wall at `60^(@)` and gets reflected without loss of speed as shown in the figure below. The value of impulse imparted by the wall on the ball will be.

Options

A. `(mv)/(2)`
B. `(mv)/(3)`
C. mV
D. 2mV

Answer

C

Explanation

`therefore Delta vec(V) = vec(V_("final")) - vec(V_("initial"))`
`rArr vec(Delta V) = (-V cos 60^(@) hat(i) - V sin 60^(@) hat(j))`
`-(V cos 60^(@) hat(i) - V sin 60^(@) hat(j))`
`rArr vec( Delta V) = (-2V cos 60^(@) hat(i))`
Thus impulse , `I = m|vec(Delta V) |`
`rArr I = m (2V cos 60