Seatwork: Express your understanding of the concept and mathematics of momentum and impulse by answering the following questions. (1whole intermediate paper) 1. Determine the momentum of a:
a) 60-kg halfback moving eastward at 9 m/s.
b) 1000-kg car moving northward at 20 m/s.
c) 40-kg freshman moving southward at 2 m/s.
2. A car possesses 20,000 units of momentum. What would be the car’s new momentum if: a) its velocity was doubled.
b) its velocity was tripled.
c) its mass was doubled (by adding more passengers and a greater load) d) both its velocity was doubled and its mass was doubled. 3. A 0.50-kg cart (#1) is pulled with a 1.0-N force for 1 second; another 0.50 kg cart (#2) is pulled with a 2.0 N-force for 0.50 seconds. a) Which cart (#1 or #2) has the greatest acceleration?
b) Which cart (#1 or #2) has the greatest impulse?
c) Which cart (#1 or #2) has the greatest change in momentum?
4. In a physics demonstration, two identical balloons (A and B) are propelled across the room on horizontal guide wires. The motion diagrams (depicting the relative position of the balloons at time intervals of 0.05 seconds) for these two balloons are shown below.
a) Which balloon (A or B) has the greatest acceleration? b) Which balloon (A or B) has the greatest final velocity? c) Which balloon (A or B) has the greatest momentum change? d) Which balloon (A or B) experiences the greatest impulse?
Assignment: Express your understanding of the concept and mathematics of the law of conservation of momentum by answering the following questions. 1. When fighting fires, a firefighter must use great caution to hold a hose that emits large amounts of water at high speeds. Why would such a task be difficult? 2. A large truck and a Mitsubishi have a head-on collision.
a. Which vehicle experiences the greatest force of impact?
b. Which vehicle experiences the greatest impulse?
c. Which vehicle experiences the greatest momentum change?
d. Which vehicle experiences the greatest acceleration?
3. Leizel and Patrick are riding in a bus at highway speed on a nice summer day when an unlucky bug splatters onto the windshield. Leizel and Patrick begin discussing the physics of the situation. Leizel suggests that the momentum change of the bug is much greater than that of the bus. After all, argues Leizel, there was no noticeable change in the speed of the bus compared to the obvious change in the speed of the bug. Patrick disagrees entirely, arguing that that both bug and bus encounter the same force, momentum change, and impulse. Who do you agree with? Support your answer. 4. A 120 kg lineman moving west at 2 m/s tackles an 80 kg football fullback moving east at 8 m/s. After the collision, both players move east at 2 m/s. Draw a vector diagram in which the before- and after-collision momenta of each player is represented by a momentum vector. Label the magnitude of each momentum vector. 5. A baseball player holds a bat loosely and bunts a ball. Express your understanding of momentum conservation by filling in the tables below.
6. A 0.25 kg baseball is thrown in air at 15 m/s and hits a 2kg bat moving at 10 m/s. after hitting the baseball, the baseball moves to the opposite direction at a velocity of 25 m/s. What is the velocity of the bat?
Quiz: Express your understanding of the concept and mathematics of momentum and impulse and the law of conservation of momentum by answering the following questions. 1. A laboratory cart with a mass of 5 kg rolls through a distance of 2m in 10 s. Which of the following mathematical statements can be used to determine the momentum?
a. 5kg + 10s/2m
b. 5kg + 2m/10s
c. 5kg x (10s/2m)
d. 5kg x (2m/10s)
2. Which two quantities can be expressed using the same units?
a. momentum and energy
b. impulse and momentum
c. impulse and force
d. energy and force
3. A 1000 kg empty cart moving with a speed of 6 m/s is about to collide with a stationary loaded cart having a total mass of 5000 kg. After collision, the carts lock and move together. [Assume friction is negligible.] Calculate the speed of the combined carts after the collision. (1m/s) 4. A 50 kg student threw a 0.40 kg ball with a speed of 20m/s. what was the magnitude of the impulse that the student exerted on the ball? (8Ns) 5. A 60 kg student jumps down from a laboratory counter. At the instant he lands on the floor his speed is 3 m/s. If the student stops in 0.2 s, what is the average force of the floor on the student? (900 kg m/s) 6. A 1000 kg car travelling due east at 15 m/s is hit from behind and receives a forward impulse of 6000 Ns. Determine the magnitude of the car’s change in momentum due to this impulse in kg m/s. (6000 kg m/s) 7. A 2kg body is initially travelling with a velocity of 40 m/s east.
If a constant force of 10 N due to east is applied to the body for 5 s, what is the final speed of the body? (65m/s) 8. On a road, a car with a mass of 1.1 x 10^3 kg collides head-on with a van having a mass of 2.5 x 10^3 kg traveling at 8 m/s. As a result of the collision, the vehicles locked together and immediately come to rest. Calculate the speed of the car immediately before the collision. (18.18) 9. A mother pushes her 120 Newton child, who is sitting on a swing. If the mother exerts a 10 N force on the child for half a second, what is the magnitude of the impulse imparted to the child by the mother? (5Ns) 10. A 2000-kg car traveling at 20 m/s collides with a 1000-kg car at rest at a stop sign. If the 2000-kg car has a velocity of 6.67 m/s after the collision, find the velocity of the 1000-kg car after the collision. (26.67 m/s)