1. Momentum Practice Problems Physics

2. Problem #1 A 1500 kg car traveling +6 m/s collides with a 2000 kg truck at rest. The vehicles collide, but do not stick together. The car has a velocity of -3 m/s after the collision. What is the velocity of the truck after the collision? m 1 v 1 + m 2 v 2 = m 1 v 1 + m 2 v 2 Initial: m 1 = 1500 kg v 1 = +6 m/s m 2 = 2000 kg v 2 = 0 Final: m 1 = 1500 kg v 1 = -3m/s m 2 = 2000 kg v 2 = ? 1500*6 + 2000*0 = 1500*-3 + 2000*v 2 9000 + 0 = -4500+ 2000*v 2 13500 = 2000*v 2 6.75 m/s = v 2

3. Problem #2 A 1500 kg car traveling +6 m/s collides with a 2000 kg truck at rest. The vehicles collide, but and DO stick together. What is the velocity of the objects after the collision? m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v f Initial: m 1 = 1500 kg v 1 = +6 m/s m 2 = 2000 kg v 2 = 0 Final: m 1 = 1500 kg m 2 = 2000 kg v f = ? 1500*6 + 2000*0 = (1500 +2000)v f 9000 + 0 = 3500*v f 9000 = 3500*v f 2.57 m/s = v 2

4. Problem #3 A 92 kg fullback, running 5 m/s attempts to drive directly across the goal line for a touchdown. Just as he reaches the line, he is met head on by two 75 kg linebackers, both moving in the opposite direction as the fullback. One linebacker is moving 2 m/s and the other is moving 4 m/s. They all become entangled in one mass after the collision. Does the fullback score a touchdown? m 1 v 1 + m 2 v 2 + m 3 v 3 = (m 1 + m 2 + m 3 ) v f Initial: m 1 = 92 kg v 1 = +5 m/s m 2 = 75 kg v 2 = -2 m/s m 3 = 75 kg v 3 = -4 m/s 0.041 m/s = v f Final: m 1 = 92 kg m 2 = 75 kg m 3 = 75 kg v f = ? Yes…He has a positive velocity. He scores a touchdown.

5. Purpose: Experimentally (and mathematically) prove conservation of momentum in a collision or an explosion. Lab: Conservation of Momentum

6. Procedure: Develop and perform an experiment to prove conservation of momentum. Results should show: momentum before an event = momentum after an event. within  10%. Lab: Conservation of Momentum

7. Things to consider: Explosion, elastic collision or inelastic collision? Will masses stay constant throughout the event? What materials will give good data? What measurement tools will you use? How to measure velocities and masses before and after the event?

8. Before beginning the experiment: Write down anticipated procedure and a materials list, then get materials. Do preliminary experiments to make sure your technique will work. Think through equations to make sure to measure and record correct data. Make a data table to use during experiment. Get teacher initials on prep sheet, before starting the experiment.