Question 1
Momentum is an idea that combines mass and velocity into one package. It is an idea that is similar to __________ and ______________.
inertia, kinetic energy
a change in momentum
impulse
Type of collision where kinetic energy is changed into other energy such as sound or heat energy.
inelastic collision
What happens to the momentum in elastic collision?
momentum is conserved and won't change
What is the formula used in the second law of motion?
F = ma
Enumerate the units for momentum, mass, and velocity.
p = kg m/s
m = kg
v = m/s
What does △ mean?
delta / change in quantity
This occurs when one object strikes another.
collision
What does mA in collision stands for?
mass of the first body/object
What does v’B stands for?
final velocity of the second body/object
A 0.50 kg football is thrown with a velocity of 15 m/s. A stationary receiver catches the ball and brings it to rest in 0.020 s. What is the force exerted on the receiver?
F = 375 N
What happens to the kinetic energy of the objects in inelastic collision?
Kinetic energy is changed into other energy such as sound or heat energy.
The momentum of a 3000 kg truck is 63, 600 kg·m/s. At what speed is the truck traveling?
v = 21. 2 m/s
What is the difference between potential energy and kinetic energy?
Potential energy - energy stored in an object that is at rest
Kinetic energy - energy in an object that is in motion.
What is the difference between momentum and impulse?
Momentum is the product of mass and velocity. Impulse is the change in momentum.
What is the formula we use in inelastic collision?
mAvA + mBvB = v (mA + mB )
Jeanne rolls a 7.0-kg bowling ball down the alley for the league championship. One pin is still standing, and Jeanne hits it head-on with a velocity of 9.0 m/s. The 2.0-kg pin acquires a forward velocity of 14.0 m/s. What is the new velocity of the bowling ball?
mA = 7.0 kg
vA = 9.0 m/s
mB = 2.0 kg
vB = 0 m/s
v'B = 14.0 m/s
v'A = 5.0 m/s
Discuss the Law of Inertia.
An object at rest will remain at rest and an object in motion will stay in motion unless acted upon by an unbalanced force.
What is the formula we use in elastic collision?
mAvA + mBvB = mAv’A + mBv’B
Before Collision:
mA= 0.15 kg
vA = 45 m/s
mB = 0.25 kg
vB = 0 kg
v =???
v = 16.88 m/s
Sometimes the curiosity factor at the scene of a car accident is so great that it actually produces secondary accidents as a result, while people watch to see what is going on. If an 800.-kg sports car slows to 13.0 m/s to check out an accident scene and the 1200.-kg pick-up truck behind him continues traveling at 25.0 m/s, with what velocity will the two move if they lock bumpers after a rear-end collision?
mA = 800 kg
mB = 1200 kg
vA = 13 m/s
vB = 25 m/s
v =20.2 m/s
A 1250 kg car is moving down the highway with a velocity of 32.0 m/s when it bumps into the car ahead of it which has a mass of 875 kg and a velocity of 25.0 m/s. After the collision, the two cars stick together. What will be the resulting velocity of the two cars together?
v = 29.12 m/s
Tom and his twin brother Tim have a combined mass of 200.0 kg and are zooming along in a 100.0-kg amusement park bumper car at 10.0 m/s. They bump Melinda’s car, which is sitting still. Melinda has a mass of 25.0 kg. After the elastic collision, the twins continue ahead with a speed of 4.12 m/s. How fast is Melinda’s car bumped across the floor?
mA = 300 kg
mB = 125 kg
vA = 10 m/s
vB = 0 m/s
v'A = 4.12 m/s
v'B = 14.11m/s
A 45.0 kg ice skater stands at rest on the ice. A friend tosses the skater a 5.0 kg ball. The skater and the ball then move backwards across the ice with a speed of 0.5 m/s. What was the speed of the ball at the moment just before the skater caught it?
v = 5 m/s
Suppose that you have a mass of 45.7 kg and are standing on frictionless roller skates. Someone then throws you a 2.50 kg mass with a velocity of 14.5 m/s and you catch it. What will be your resultant velocity?
v = 0.75 m/s