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 = -11 N then calculate the impulse delivered to a 3-kg mass during the 5 seconds graphed above.
-7.5 N sec3.5 N sec36.5 N sec47.5 N sec7 N sec

		Question 2 If the object's initial velocity in Question 1 was 6.4 m/sec, what will be its final velocity at the end of these 5 seconds?
-5.2 m/sec3.9 m/sec7.6 m/sec22.7 m/sec3.3 m/sec

		Question 3 What was the magnitude of the average force acting on the 3-kg mass in Question 1 during the 5 seconds displayed on the graph?
4.5 N17.5 N0.7 N-1.5 N7.3 N

		Question 4 A 6.4-gram bullet moving at 270 m/sec travels through a block of wood and emerges out the other side moving at 210 m/sec. If it takes 29.1 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?
-1.32 x 10⁴ N5.94 x 10⁴ N4.62 x 10⁴ N1.06 x 10⁶ N

		Question 5 During target practice, a man shoots a 6.4-gram bullet with a horizontal velocity of 210 m/sec at a 1.5-kg wooden block balanced on the top of a 1.1-meter tall fence post. If the bullet embeds in the block, how fast will the block-bullet be knocked off the post?
0.89 m/sec209.11 m/sec140 m/sec0.046 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?
0.99 m0.42 m0.2 m0.7 m0.3 m

		Question 7 A second 6.4-gram bullet is fired at another 1.5-kg block which is initially at rest on a table. The bullet embeds in the block resulting in the block sliding 151 centimeters before coming to a stop. The coefficient of friction between the block and the table's surface is µ = 0.373. How much work will the friction between the table and block do on the block while bringing it to a stop?
56.3 J8.3 J22.3 J3.6 J5.5 J

		Question 8 How fast was the original bullet in Question 7 travelling before it struck the block?
781.3 m/sec208.2 m/sec409.8 m/sec332 m/sec415 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 11 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?

3 kg m/sec15.2 kg m/sec7.6 kg m/sec5.5 kg m/sec7 kg m/sec

		Question 10 Within the system, what fraction of the 1-kg ball's original KE remains after the collision?
0.1980.640.80.4450.312