A ball of mass m moving with velocity v, collide with the wall elastically as shown in the figure. After impact the change in angular momentum about P is:

Question

G1 Physics · Accepted Answer

Use angular momentum L⃗=r⃗×p⃗ (or L=Iω for a rigid body). During a short impact, angular momentum about a point with zero impulsive torque is conserved; use linear momentum/energy additionally where applicable. This gives 2mvdcosθ.