In a football game, one player (a "tackle") running at a constant speed of 5 m/s tackles another player (a "receiver") who is initially stationary. The two players fly off together horizontally at 3 m/s, before they hit the ground and begin to slow down. If the mass of the tackle is 140 kg, a.) What is the mass of the receiver? kg b.) Calculate the kinetic energy of the tackle-receiver system before and after the collision. KESYS, i = KESYS, f = (Did the mechanical energy of the system increase, decrease, or stay the same?) c.) What kind of collision is this v ---Select--- elastic (Did you need to do part b to be somewhat inelastic completely inelastic

A rocket is propelled forward as very high speed gases are ejected out of its back. Which one of the following is the best explanation as to why the rocket is propelled forward? The high speed gases push on the rocket as they are ejected and propel it forward. B) The rocket is propelled forward because both energy and momentum must be conserved. The rocket is propelled forward due to the conservation of momentum. Because the gases are pushing against the air, the air propels the rocket forward.

The following are multiple choice questions. No explanations required.Choose the correct answer    g) Two balls are dropped from the same height. Both balls bounce (perfectly elastic) when they hit theground. Ball A has half the mass of ball B. Which ball has a greater speed after the bounce?h) Two balls are thrown from the same initial height above the ground. Ball A is thrown straight down.Ball B is thrown straight up. Both balls have the same initial speed. Which ball has the larger speedwhen it hits the ground?i) Two identical balls roll down a frictionless track. The tracks are the same height from top to bottom.Track A is straight and track B is curved. If both balls are released from rest, which ball reaches thebottom with the larger speed?j) You see two identical freight trucks driving down the highway. In both cases, the trailer is bouncing upand down on its springs. Truck A is heavier than truck B. Which truck bounces with a higher frequency?

Two 3.0 g bullets are fired with speeds of 40.0 m/s and 80.0 m/s respectively. What are their kinetic energies? Which bullet has more kinetic energy? What is the ratio of their kinetic energies?