Momentum and Energy

Practice Problems
Momentum and Energy

Directions: On this worksheet you will be investigating the relationships between momentum and energy.

		Question 1 If F_max = 20 N and F_min = -13 N then calculate the impulse delivered to a 2-kg mass during the 5 seconds graphed above.
-12.5 N sec39.5 N sec52.5 N sec0.5 N sec1 N sec

		Question 2 If the object's initial velocity in Question 1 was 6.8 m/sec, what will be its final velocity at the end of these 5 seconds?
-6.6 m/sec3.6 m/sec7 m/sec0.5 m/sec14.1 m/sec

		Question 3 What was the magnitude of the average force acting on the 2-kg mass in Question 1 during the 5 seconds displayed on the graph?
2.5 N3.5 N7.9 N0.1 N-2.5 N

		Question 4 A 6.8-gram bullet moving at 300 m/sec travels through a block of wood and emerges out the other side moving at 200 m/sec. If it takes 27.6 µsecs (1 µsec = 1 x 10^-6 seconds) for the bullet to bore through the wood, what average force did the wood exert on the bullet?
-2.46 x 10⁴ N1.23 x 10⁶ N7.39 x 10⁴ N4.93 x 10⁴ N

		Question 5 During target practice, a man shoots a 6.8-gram bullet with a horizontal velocity of 200 m/sec at a 1-kg wooden block balanced on the top of a 1.3-meter tall fence post. If the bullet embeds in the block, how fast will the block-bullet be knocked off the post?
198.65 m/sec1.35 m/sec200 m/sec0.034 m/sec

		Question 6 After being knocked off, how far from the base of the fence post will the block in Question 5 hit the ground?
1.02 m0.49 m0.72 m0.36 m0.7 m

		Question 7 A second 6.8-gram bullet is fired at another 1-kg block which is initially at rest on a table. The bullet embeds in the block resulting in the block sliding 166 centimeters before coming to a stop. The coefficient of friction between the block and the table's surface is µ = 0.379. How much work will the friction between the table and block do on the block while bringing it to a stop?
6.2 J62.9 J3.7 J16.4 J2.3 J

		Question 8 How fast was the original bullet in Question 7 travelling before it struck the block?
350.9 m/sec519.6 m/sec310 m/sec402.6 m/sec233.9 m/sec

Question 9 As shown in the diagrams provided below, a ball of mass 1 kg is originally moving along the x-axis with a velocity of 13 m/sec towards the origin. As it approaches the origin, it delivers a glancing blow to a stationary 2-kg mass. After the collision, the 1-kg ball continues traveling towards the left, into the second quadrant, at a reduced speed of 5 m/sec at an angle of 37º above the negative x-axis.

What is the final momentum of the 2-kg mass after the collision?

9.5 kg m/sec9 kg m/sec6.5 kg m/sec19 kg m/sec3 kg m/sec

		Question 10 Within the system, what fraction of the 1-kg ball's original KE remains after the collision?
0.1720.2440.750.5620.415