Momentum
If a particle's kinetic energy is zero, what is its momentum?
0
If an object is not moving, what is its momentum?
0
In inelastic, ∆KE does not equal
0
Total Kinetic Energy Equation
1/2m1v1^2 + 1/2m2v2^2
frequency =
1/T
What is momentum?
A vector quantity that is the product of mass and velocity
What is Hooke's Law equation?
F = -kx
What is impulse equal to?
F x t
What does impulse do?
It causes a change in momentum
In elastic, KE is conserved, so ∆KE =
KEf - KEi
What will objects colliding(or pushing apart) experience?
Momentum
If two objects collide and one is initially at rest, is it possible for one to be at rest after the collision?
Yes, if the other objects moves with the same velocity.
Two skaters initially at rest push against each other so they move in opposite directions. What is their total momentum when they begin moving?
Zero, because momentum is conserved.
In elastic collision, objects _____
collide and return to their original shape
Linear momentum between colliding objects is always _____
conserved
In SMH, objects oscillate with ____
constant amplitude.
T = seconds/ ____
cycles
Gravity _____ with altitude
decreases
Kinetic energy between colliding objects may be lost due to:
friction, which becomes heat
In SMH, greater displacement = _____
greater restoring force
Impulse Momentum Theorem aka
impulse causes a change in momentum
What unit is momentum(p) in?
kg x m/s
m1v1i+m2v2i = m1v1f + m2v2f is
law of conservation of energy
The only thing that affects a pendulum's period is
length
In T= 2π√L/g the L stands for
length of pendulum (m)
In T = 2π√m/k the m stands for
mass on spring (kg)
In elastic collision, what is conserved?
momentum and kinetic energy
F∆t=
mvf-mvi
Inelastic Collisions happen when kinetic energy is ____
not conserved when objects collide
Restoring force and displacement point in
opposite directions
What is the equation for momentum?
p=mv
T= 2π√L/g is for a
pendulum
If objects stick together after colliding, and move with the same velocity, it's called
perfectly inelastic
In T = 2π√m/k the T stands for
period
When length of pendulum decreases,
period decreases
When gravity decreases,
period increases
In F=-kx, k is always
positive
In SMH, vibration about an equilibrium position in which the "restoring force" is ______
proportional to the displacement from equilibrium
For springs, the restoring force is exerted by the spring to
restore itself to equilibrium
T= 2π√m/k is for a
spring
In T = 2π√m/k the k stands for
spring constant (N/m)
Objects with greater momentum are harder to
stop
Gymnasts always perform on padded mats, because
the impulse is longer than it would be without the mat.
What does Newtons 3rd Law state?
Every action has an equal and opposite reaction.
In F=-kx, what does x stand for?
Displacement(m)
What is the equation for impulse momentum?
F∆t=∆p
What unit is impulse in?
N x s
If two particles have = kinetic energies, do they have the same momentum?
No, because KE = 1/2 mv^2 and p=mv
When force is exerted on an object, will a 1000N force always produce a larger change in the objects momentum than a 100 N force does?
No, it depends on the time, etc.
Is momentum ever lost?
No, just transferred between objects within a system
In an elastic collision between two objects, do both objects have the same kinetic energy after the collision as before?
No, kinetic energy is conserved between them.
In a collision between two soccer balls, momentum is conserved. Is it conserved for each soccer ball?
No, only total momentum is conserved.
If two objects collide and one is initially at rest, is it possible for both to be at rest after the collision?
No, since initial momentum is not zero, final momentum can't be zero.
Explain how momentum is conserved when a ball bounces against a floor.
Part of the momentum is transferred to the earth.
In F=-kx, what does F stand for?
Restoring force (N)
What does SHM stand for?
Simple Harmonic Motion
In F=-kx, what does k stand for?
Spring constant (N/m)
A truck loaded with sand is moving down the highway in a straight path. What happens to the momentum of the truck if the sand leaks at a constant rate through a hole in the truck bed while the truck maintains a constant velocity?
The momentum decreases
A truck loaded with sand is moving down the highway in a straight path. What happens to the momentum of the truck if the trucks velocity is increasing?
The momentum increases
What is impulse?
The product of force and time
Consider a perfectly inelastic head-on collision between a small car and a large truck traveling at the same speed. Which vehicle has a greater change in kinetic energy as a result of the collision?
The truck, because its mass is larger
What is the Law of Conversation of Momentum?
Total momentum of objects interacting with each other remains constant, regardless of the forces between them.
