Question

Q1. In the old (ish) movie Deep Impact, an asteroid is headed straight for earth at a velocity of 30 km/s! Astronauts try to save the earth by blowing the asteroid into two pieces. One piece is smaller, with a mass of 2.2 x 1013 kg, and the other is 4.7 x 1014 kg. But.... their mission is not successful, and the two pieces remain on the same trajectory, heading straight for earth. A) After the explosion, the smaller piece moves twice as fast as the larger piece. Calculate the velocities of the two fragments after the explosion. (5 pts) B) Is an explosion elastic or inelastic? Explain your answer (2pts) Q2. A 0.15 kg baseball is pitched at 42 m/s and hit back at 55 m/s. A) Is the momentum of the ball conserved? Explain your answer. (2 pts) B) Sketch a graph that shows the force of the bat on the ball as a function of time during the collision. (2 pts) C) Find the average force on the ball if the collision takes 6 ms? (2 pts)

Answer 1

(2) A) Inital momentum = 0.15 (42) &-6.3 kg mis final momentum = o.15ASS = 8.25 kg mbo Momentum of ball does not lomain conserved. . 6 x 10-3 F = $b - (8.25 -(-6.3)) - (2425]N (A) using conservation of momentum (2.2 1103 + 47110lt) x 10 kugle = 2.2410² V, +47X10²V. Put va 2 V2 - -) (B) Ei – Ef - 60.35 kuulsee - 2k = 120.70 kms – X (2.2x1013 +4.74104) & (30x1000) 2. 24. 23 & & [ 2.2110² (120 70 +63) + (4.74104) (60.35, 18) 27 Inolastic Explosion - 1.01 x 1024 ]