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 = 18 N and F_min = -13 N then calculate the impulse delivered to a 5-kg mass during the 5 seconds graphed above.
-3 N sec50.5 N sec-14.5 N sec-1.5 N sec37.5 N sec

		Question 2 If the object's initial velocity in Question 1 was 7.5 m/sec, what will be its final velocity at the end of these 5 seconds?
7.2 m/sec-7.8 m/sec4.6 m/sec36 m/sec1.2 m/sec

		Question 3 What was the magnitude of the average force acting on the 5-kg mass in Question 1 during the 5 seconds displayed on the graph?
2.5 N7.5 N-2.9 N-7.5 N-0.3 N

		Question 4 A 7.5-gram bullet moving at 280 m/sec travels through a block of wood and emerges out the other side moving at 220 m/sec. If it takes 27.3 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?
7.69 x 10⁴ N1.37 x 10⁶ N6.04 x 10⁴ N-1.65 x 10⁴ N

		Question 5 During target practice, a man shoots a 7.5-gram bullet with a horizontal velocity of 220 m/sec at a 2.5-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?
219.34 m/sec0.66 m/sec88 m/sec0.085 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?
0.18 m0.34 m0.8 m0.24 m1.13 m

		Question 7 A second 7.5-gram bullet is fired at another 2.5-kg block which is initially at rest on a table. The bullet embeds in the block resulting in the block sliding 164 centimeters before coming to a stop. The coefficient of friction between the block and the table's surface is µ = 0.36. How much work will the friction between the table and block do on the block while bringing it to a stop?
59 J14.5 J8.8 J40.3 J5.4 J

		Question 8 How fast was the original bullet in Question 7 travelling before it struck the block?
1137 m/sec250 m/sec453.4 m/sec725 m/sec340.1 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 kg m/sec6.5 kg m/sec9.5 kg m/sec3 kg m/sec19 kg m/sec

		Question 10 Within the system, what fraction of the 1-kg ball's original KE remains after the collision?
0.1720.750.5620.4150.244