## Question:

The collar B of weight ${ W }_{ B }$ is at rest, and when it is in the position shown the spring is unstretched. If another collar A of weight ${ W }_{ A }$ strikes it so that B slides a distance b on the smooth rod before momentarily stopping, determine the velocity of A just after impact, and the average force exerted between A and B during the impact if the impact occurs in time Δt. The coefficient of restitution between A and B is e. Units Used: kip = ${ 10 }^{ 3 }$ lb Given: ${ W }_{ B }$= 10 lb , ${ W }_{ A }$ = 1 lb , k = 20 lb/ft , g = ${ 32.2ft/s }^{ 2 }$ , a = 3 ft , b = 4 ft , Δt = 0.002 s , e = 0.5