Linear Momentum and Force
What is the formula for linear momentum?
p = mv (momentum = mass × velocity).
What is the formula for impulse?
Impulse = Force × Time
State the law of conservation of momentum.
The total momentum of a closed system remains constant if no external forces act on it.
What is an elastic collision?
A collision in which the objects that collide push each other away.
What is an inelastic collision?
A collision in which the objects that collide stick together afterwards.
What are the units of linear momentum?
Kilogram meters per second (kg·m/s).
How is impulse related to momentum?
Impulse is equal to the change in momentum
In an isolated system, what happens to the total momentum before and after a collision?
It remains the same.
In an elastic collision, what quantities are conserved?
Both momentum and kinetic energy.
What happens to kinetic energy in a perfectly inelastic collision?
It is converted into other forms of energy like heat or deformation energy.
How does Newton’s second law relate force to momentum?
F = dp/dt (force equals the rate of change of momentum).
What are the units of impulse?
Newton seconds (N·s) or kg·m/s.
How does conservation of momentum apply in two-dimensional collisions?
The total momentum is conserved in both the x and y directions.
Give an example of an elastic collision.
Collisions between billiard balls.
Give an example of an inelastic collision
Two cards collide head on.
What is the momentum of a 3 kg object moving at 4 m/s?
12 kg·m/s.
What happens to an object’s momentum if an impulse is applied to it?
The object’s momentum changes.
If two objects collide and stick together, what type of collision is it?
Perfectly inelastic collision.
Two objects collide elastically. If one is initially at rest, what happens to their velocities?
Their velocities exchange if they have equal mass.
During a car crash, why is some kinetic energy lost?
It is converted into sound, heat, and deformation energy.