 Practice Problems Momentum and Energy

Directions: On this worksheet you will be investigating the relationships between momentum and energy. Question 1  If Fmax = 20 N and Fmin = -14 N then calculate the impulse delivered to a 4-kg mass during the 5 seconds graphed above. -1 N sec-2 N sec55 N sec-15 N sec41 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? 3.8 m/sec7.2 m/sec29 m/sec1.6 m/sec-7.8 m/sec Question 3  What was the magnitude of the average force acting on the 4-kg mass in Question 1 during the 5 seconds displayed on the graph? 3 N-0.2 N-3 N8.2 N-5 N Question 4  A 7.5-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 25.7 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? 1.37 x 106 N-1.46 x 104 N7.59 x 104 N6.13 x 104 N Question 5  During target practice, a man shoots a 7.5-gram bullet with a horizontal velocity of 210 m/sec at a 2-kg wooden block balanced on the top of a 1.4-meter tall fence post. If the bullet embeds in the block, how fast will the block-bullet be knocked off the post? 0.071 m/sec209.22 m/sec105 m/sec0.78 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? 0.79 m0.22 m0.29 m0.42 m1.12 m Question 7  A second 7.5-gram bullet is fired at another 2-kg block which is initially at rest on a table. The bullet embeds in the block resulting in the block sliding 175 centimeters before coming to a stop. The coefficient of friction between the block and the table's surface is µ = 0.355. How much work will the friction between the table and block do on the block while bringing it to a stop? 62.1 J34.4 J7 J4 J12.2 J Question 8  How fast was the original bullet in Question 7 travelling before it struck the block? 933.2 m/sec610 m/sec256.2 m/sec441.6 m/sec348.6 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 14 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? Question 10  Within the system, what fraction of the 1-kg ball's original KE remains after the collision? 0.1620.4030.5310.210.729