Question 4: Larry has a mass of 80 kg and runs across the front of the classroom with a speed of 4 m/s and jumps onto a giant skateboard. The skateboard is initially at rest and a mass equal to Larry's. If friction with the floor is negligible, what is the speed of Larry and the skateboard after he jumps on board?

Gayle runs at a speed of 4.15 m/s and dives on a sled, initially at rest on the top of a frictionless snow-covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back and together they continue down the hill. What is their speed at the bottom of the hill if the total vertical drop is 15.0 m? Gayle's mass is 45.0 kg, the sled has a mass of 5.05 kg and her brother has a mass of 30.0 kg. m/s

A rock (rock 1) is flying in the sky towards another rock, rock 2. Rock 1 has a mass of 60 kg, and Rock 2 has a mass of 10 kg. Rock 1 is in the sky with a speed of 25 m/s towards Rock 2, and rock 2 is movingtowards Rock 1 in the opposite direction with a speed of 35 m/s. If the two rocks stick together, what is their final velocity? Ignore air resistance and gravity. Is there a change in the kinetic energy of the system? If so, what is it?

Gayle runs at a speed of 3.60 m/s and dives on a sled, initially at rest on the top of a frictionless snow - covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back and together they continue down the hill. What is their speed at the bottom of the hill if the total vertical drop is 15.0 m? Gayle's mass is 46.5 kg, the sled has a mass of 5.10 kg and her brother has a mass of 30.0 kg.

Problem-3: A ball of mass 200 gram strikes a wall perpendicular to its surface at a speed of 10 m/s and rebounds back at the speed of 5 m/s. It is in contact with the wall for 2 milli-sec. Find the average force exerted by the wall on the ball.

a 600 gram banana sliding north on a frictionless table at 2.5 meters per second bounces of a 400 gram kiwi fruit that is initially at rest , after colliding the banana continues moving north at 0.5 meters per second. At the North edge of the track is a frictionless inclined ramp which the kiwi fruit slides up to then the kiwi comes back down the ramp , without losing energy , and will now be moving south , the kiwi will catch up and hit the banana again. How much momentum did the kiwi have just before the sticky collision ? how much just after ? how much did the kiwis momentum change ?

Gayle runs at a speed of 3.20 m/s and dives on a sled, initially at rest on the top of a frictionless snow-covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back and together they continue down the hill. What is their speed at the bottom of the hill if the total vertical drop is 15.0 m? Gayle's mass is 45.0 kg, the sled has a mass of 5.25 kg and her brother has a mass of 30.0 kg. m/s

a 600 gram banana sliding north on a frictionless table at 2.5 meters per second bounces of a 400 gram kiwi fruit that is initially at rest , after colliding the banana continues moving north at 0.5 meters per second. At the North edge of the track is a frictionless inclined ramp which the kiwi fruit slides up to then the kiwi comes back down the ramp , without losing energy , and will now be moving south , the kiwi will catch up and hit the banana again. If the last collision took 20 milliseconds , what was the average force exerted by the banana on the kiwi during the collision (magnitude and direction ) ? by the kiwi on the banana?