basics of momentum
impulse & force
Collisions
math problems
real- world applications
100
What is the formula for momentum?
P = m•v
100
Impulse is = to what change in physical quantity?
Change in momentum
100
What must be conserved in all collisions?
Momentum
100
A 2kg object moves at 3 m/s, what is its momentum?
6 kg•m/s
100
Why do athletes follow through when swinging?
They increase impulse
200
What are the units of momentum?
Kg•m/s
200
What is the formula for impulse?
200
A collision in which objects stick together is called what?
Inelastic collisions
200
A 1 kg ball at 4m/s hits a 2 kg ball at rest. Find the total momentum before collision.
4 kg•m/s
200
Why are crumple zones used in cars?
To increase collision time and reduce force
300
If velocity doubles, what happens to momentum?
It also doubles
300
Increasing the impact time does what to the force?
It reduces the force.
300
A collision that conserves both momentum and kinetic energy is called what?
Elastic collision
300
A force of 20 N acts for 0.5 seconds, what is the change in momentum?
10 N•s
300
A rocket moves forward by conservation of what?
Momentum
400
What quantity is momentum?
A vector
400
If airbags protect you from something, what do they protect you from?
From collision time.
400
True or false: kinetic energy is always conserved?
False
400
A 5 kg cart is moving at 2 m/s hits a 1 kg cart at rest, they stick together. Find the velocity?
1.67 m/s
400
Why does a heavier truck take longer to stop then a small car?
The truck has more momentum
500
What must change for an object to change its momentum?
Its velocity or mass
500
If a force of 10 N acts for 5 seconds, what is the impulse?
50 N•s
500
In an inelastic collision, what type of energy is often lost?
Mechanical kinetic energy
500
A 50 g bullet (0.05kg) is fired at 200 m/s. What is its momentum?
10 kg • m/s
500
Why does a gun recoil backward when fired?
Because of conservation of momentum.