Two children are throwing snowballs at each other atop a frozen lake with negligible friction. Both are initially at rest when one child throws a snowball (m1 m/s at the other child (m2 the child, it deforms and sticks to her jacket. The child, with 1.2 kg) with a speed of 7.3 31 kg). When the snowball hits the snowball crushed against her jacket, starts sliding across the ice as a result of the hit. What fraction of the snowball's mechanical energy was converted into heat/internal energy as it was being deformed?

A 2.76-kg steel ball strikes a massive wall at 10.0 m/s at an angle of θ = 60.0° with the plane of the wall. It bounces off the wall with the same speed and angle (see the figure below). If the ball is in contact with the wall for 0.176 s, what is the average force exerted by the wall on the ball?

An ice skater with a mass of 48.0 kg is gliding across a smooth lake with a speed of 2.85 m/s when she hits a spot of ice covered with snow. After a time of 7.75 s she has slowed to a stop. Using your knowledge of momentum, determine the magnitude of the average force of friction acting on the ice skater while she slows to a stop.

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?

A lumberjack is standing on a log floating on a lake. She starts from rest, then runs along the log to the end, when she jumps from the first log onto a second. After landing safely on the second log, she slows down and ends up standing on the second log. Both logs both have masses of 150 kg each and the mass of the lumberjack is 70 kg. The lumberjack reaches a speed of 7.0 m/s relative to the shore during her jump. What are the speeds of the two logs and of the lumberjack after she has stopped on the second log? You may assume the drag of the water on the logs is very small.

A bullet of mass mb is fired horizontally with speed vi at a wooden block of mass mw resting on a frictionless table. The bullet hits the block and becomes completely embedded within it. After the bullet has come to rest relative to the block, the block, with the bullet in it, is traveling at speed uf. (Figure 1) Figure Before collision mb mw 1 of 1 After collision ▼ Part A Which of the following best describes this collision? View Available Hint(s) Operfectly elastic O partially inelastic Operfectly inelastic Submit Part B Which of the following quantities, if any, are conserved during this collision? ►View Available Hint(s) Okinetic energy only O momentum only Okinetic energy and momentum Oneither momentum nor kinetic energy Submit P Pearson

A 1.5x105 kg barge is floating downriver in a fog with a velocity of i = m/s when it collides with a second barge with a mass of 3.0x105 kg heading across the river with a velocity of i = m/s. Immediately after impact, the second barge is headed 20° downriver with a speed of 4.5 m/s. Assume the current is negligible in this part of the river. a. What is the velocity of the second barge immediately after impact (in vector form)? b. Use conservation of momentum to find the velocity of the first barge immediately after impact (in vector form)? c. Was the collision elastic? If not, what was the change in kinetic energy? 20 Downriver

A 1200 kg car approaches a 950 kg car that is stopped at a traffic light. The initial speed of the first car is 40 mph, to the right, and it hits the second car. Both stay together moving at the same speed. What final speed do both have? 20 m/s 50 m/s 10 m/s 30 m/s