Question

7. AS kg ball is initially at rest on a horizontal frictionless surface as shown to the right. A hard plastic cube of mass 0.5 kg slides across the surface at a speed of 26 ms and strikes the ball The figure below shows a graph of the force exerted on the ball by the cube as a function of time. Oslo Force (x10'N) 10 2.0 10.0 4.0 6.0 8.0 Time (x10's) A) Determine the total impulse given to the ball. B) Determine the horizontal velocity of the ball immediately after the collision. C) Determine speed and direction of travel (if any) of the cube immediately after the collision. D) Determine the kinetic energy dissipated in the collision.

Answer 1

of (A) Total Impulse = area under the curve I force - Time graph. (10x10*+ 2x10*3)* 2x103 12 kg mis (B) Impulse = change in momentum Initial momentum of ballo let final velocity be v final momentum of ball = Sv 12 - SV-o Ve 2.4mis

Initial momentum of system : Pi = 0.5*26 +0 - 13 kgm/s final momentum of system : f = 0.5V + 5x2.4 conserving momentum, pi= Pf. 13- Osv +12 0.51 V - 2 m/s cube travels with speed 2 m/s towards right. (d) Initial kinetic energy = -x 0.5x = 1693 final Kinetic energy: fx 0.5*(23* +4x562-452 = 1 + 14.4 - 15.45 sk.€ 169 - 15.4 Kinetic energy dissipated = 153.6]