Chapter 12: Momentum. 12.1 Momentum 12.2 Force is the Rate of Change of Momentum 12.3 Angular Momentum. Chapter 12 Objectives. Calculate the linear momentum of a moving object given the mass and velocity. Describe the relationship between linear momentum and force.
Calculate the linear momentum of a moving object given the mass and velocity.
Describe the relationship between linear momentum and force.
Solve a one-dimensional elastic collision problem using momentum conservation.
Describe the properties of angular momentum in a system—for instance, a bicycle.
Calculate the angular momentum of a rotating object with a simple shape.
Investigation Key Question:
What are some useful properties of momentum?
Two balls with the same mass and speed have the same kinetic energy but opposite momentum.
A car is traveling at a velocity of 13.5 m/sec (30 mph) north on a straight road. The mass of the car is 1,300 kg. A motorcycle passes the car at a speed of 30 m/sec (67 mph). The motorcycle (with rider) has a mass of 350 kg. Calculate and compare the momentum of the car and motorcycle.
If you throw a rock forward from a skateboard, you will move backward in response.
Two 0.165 kg billiard balls roll toward each other and collide head-on.
Initially, the 5-ball has a velocity of 0.5 m/s.
The 10-ball has an initial velocity of -0.7 m/s.
The collision is elastic and the 10-ball rebounds with a velocity of 0.4 m/s, reversing its direction.
What is the velocity of the 5-ball after the collision?
(0.165 kg) v3 + (0.165 kg) (0.4 m/s)
A train car moving to the right at 10 m/s collides with a parked train car.
They stick together and roll along the track.
If the moving car has a mass of 8,000 kg and the parked car has a mass of 2,000 kg, what is their combined velocity after the collision?
(8,000 + 2,000 kg)
v3= 8 m/s
The train cars moving together to right at 8 m/s.
Starting at rest, an 1,800 kg rocket takes off, ejecting 100 kg of fuel per second out of its nozzle at a speed of 2,500 m/sec. Calculate the force on the rocket from the change in momentum of the fuel.
An artist is making a moving metal sculpture. She takes two identical 1 kg metal bars and bends one into a hoop with a radius of 0.16 m. The hoop spins like a wheel. The other bar is left straight with a length of 1 meter. The straight bar spins around its center. Both have an angular velocity of 1 rad/sec. Calculate the angular momentum of each and decide which would be harder to stop.