Momentum
True or False:
A stationary object has momentum.
false
Impulse causes a change in what quantity?
Momentum
Name one safety device that reduces injury by increasing time of impact.
Answer: Seatbelt / Helmet / Airbag
what is the formula for momentum?
p= mass x velocity
If a car has high momentum, what must happen to stop it?
we must apply force.
To reduce injury in a crash, should time of impact increase or decrease?
Increase
Momentum depends on two things. What are they?
mass and velocity
What happens to force if the time of impact increases?
Force decreases
I= Force x time
Which has greater momentum:
A bike (100 kg) moving at 20 m/s OR
A truck (2000 kg) moving at 2 m/s?
Bike → 2000 kg·m/s
Truck → 4000 kg·m/s
Truck has greater momentum
True or false
When a boxer moves their head backward during a punch, the impact time increases, which reduces the force of the punch.
true
A hammer produces an impulse of 120 N·s in 0.3 s.
Find the force.
400 N
A ball has momentum of 200 kg·m/s and velocity 10 m/s.
Find the mass.
20 kg
A ball's momentum changes from 20 kg·m/s to 0.
What happened?
stopped the ball
A soccer ball experiences an impulse of 60 N·s when kicked for 0.2 s.
Find the force.
300 N