A $20$lb block at A has a spring attached to it $(k=4l\frac{b}{f}t).$ The spring has an unstretched length of $4$ feet. The block is pushed against the spring, as shown, and released from rest. The block travels on a smooth surface to point $2.$ At point $2$ a sharp notch cuts the spring, and the block continues to travel the path without the spring until it collides with ball C which weighs $40-lb.$ After the collision ball C travels $9\mathrm{.}434$ feet on a surface with a coefficient of friction of $0\mathrm{.}3.$ At the end of the horizontal length, ball C is launched horizontally and bounces on the smooth inclined surface at D$.$ Determine: a$)$ speed at position $2,b)$ normal force at position $2($before the spring is cut$),$ c$)$ speed of the block before impact, d$)$ speed of the block and ball after the impact, e$)$ speed of the ball$($C$)$ before becoming a projectile, f$)$ speed of rebound at D $.$ The coefficient of restitution for all impacts is $0\mathrm{.}8.$

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