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 = 19 N and F_min = -10 N then calculate the impulse delivered to a 3-kg mass during the 5 seconds graphed above.
8 N sec-6 N sec44 N sec4 N sec34 N sec

		Question 2 If the object's initial velocity in Question 1 was 7.8 m/sec, what will be its final velocity at the end of these 5 seconds?
9.1 m/sec5.8 m/sec-6.5 m/sec27.4 m/sec3.9 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 N0.8 N20 N6.8 N-1.2 N

		Question 4 A 7.8-gram bullet moving at 300 m/sec travels through a block of wood and emerges out the other side moving at 240 m/sec. If it takes 27.9 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?
8.39 x 10⁴ N6.71 x 10⁴ N1.51 x 10⁶ N-1.68 x 10⁴ N

		Question 5 During target practice, a man shoots a 7.8-gram bullet with a horizontal velocity of 240 m/sec at a 1.5-kg wooden block balanced on the top of a 1-meter tall fence post. If the bullet embeds in the block, how fast will the block-bullet be knocked off the post?
0.049 m/sec1.24 m/sec238.76 m/sec160 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?
0.56 m0.25 m0.4 m0.76 m1.08 m

		Question 7 A second 7.8-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 165 centimeters before coming to a stop. The coefficient of friction between the block and the table's surface is µ = 0.372. How much work will the friction between the table and block do on the block while bringing it to a stop?
24.4 J3.3 J61.4 J9.1 J5.5 J

		Question 8 How fast was the original bullet in Question 7 travelling before it struck the block?
455 m/sec347.4 m/sec671.6 m/sec414.2 m/sec265.6 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 10 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?

13.4 kg m/sec6 kg m/sec5 kg m/sec6.7 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?
0.4740.6970.8350.2250.369