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 = -12 N then calculate the impulse delivered to a 3-kg mass during the 5 seconds graphed above.
2 N sec50 N sec-10 N sec38 N sec4 N sec

		Question 2 If the object's initial velocity in Question 1 was 7 m/sec, what will be its final velocity at the end of these 5 seconds?
3.7 m/sec23 m/sec3 m/sec7.7 m/sec-6.3 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?
-2 N7.6 N0.4 N10 N4 N

		Question 4 A 7-gram bullet moving at 260 m/sec travels through a block of wood and emerges out the other side moving at 210 m/sec. If it takes 25.5 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?
1.29 x 10⁶ N-1.37 x 10⁴ N7.14 x 10⁴ N5.76 x 10⁴ N

		Question 5 During target practice, a man shoots a 7-gram bullet with a horizontal velocity of 210 m/sec at a 1.5-kg wooden block balanced on the top of a 1.2-meter tall fence post. If the bullet embeds in the block, how fast will the block-bullet be knocked off the post?
140 m/sec0.98 m/sec209.02 m/sec0.05 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?
0.34 m0.24 m1.03 m0.73 m0.48 m

		Question 7 A second 7-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 157 centimeters before coming to a stop. The coefficient of friction between the block and the table's surface is µ = 0.399. How much work will the friction between the table and block do on the block while bringing it to a stop?
9.3 J62.6 J3.8 J5.9 J23.2 J

		Question 8 How fast was the original bullet in Question 7 travelling before it struck the block?
241 m/sec351.3 m/sec426.6 m/sec465 m/sec756.3 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 12 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?

6 kg m/sec8.5 kg m/sec17 kg m/sec3 kg m/sec8 kg m/sec

		Question 10 Within the system, what fraction of the 1-kg ball's original KE remains after the collision?
0.2660.180.5940.4240.771