Momentum
http://science360.gov/obj/video/d0e16d27-05d4-4511-9394-2758aa066981
• Momentum -“mass in motion”
–Mass = How much of
something there is.
–Motion = any movement or
change in position or time.
Variables
• Momentum depends on: how
much stuff is moving (mass)
and how fast the stuff is
moving (velocity).
• What else depends on mass
and velocity?
Formula
• P=M*V
• In physics, the symbol for momentum is p.
• M is mass (in kg)
• V is velocity in (m/s)
• Unit of momentum (p) = kg * m/s
Is Momentum Vector or Scalar?
Check For Understanding
1. Determine the momentum of a ...
a. 60-kg halfback moving eastward at 9 m/s.
60 * 9 = 540 kg * m/s
b. 1000-kg car moving northward at 20 m/s.
1000 * 20 = 20,000 kg * m/s
c. 40-kg freshman moving southward at 2 m/s.
40 * 2 = 80 kg * m/s
What does the equation mean?
• Momentum is DIRECTLY PROPORTIONAL to
both mass and velocity.
Check For Understanding
1. A car possesses 20,000 units of momentum.
What would be the car's new momentum if ...
• a. its velocity was doubled.
• b. its velocity was tripled.
• c. its mass was doubled (by adding more
passengers and a greater load)
• both its velocity was doubled and its mass was
doubled.
Check For Understanding
1. A car possesses 20,000 units of momentum.
What would be the car's new momentum if ...
• a. its velocity was doubled. 40,000
• b. its velocity was tripled. 60,000
• c. its mass was doubled (by adding more
passengers and a greater load) 40,000
• both its velocity was doubled and its mass was
doubled. 80,000 (quadruple)
• Momentum of stationary object = 0
• KE of stationary object = ?
Exit Ticket
1.
2.
3.
What is the equation for momentum? p = ______________
What units are used to measure momentum? ____________________
Which has more momentum, a ping-pong ball or a bowling ball?
Assume both are moving with the same velocity. EXPLAIN YOUR
ANSWER!
4. Which has more momentum, a car going 5 mph or a car speeding down
the highway at 65 mph? EXPLAIN YOUR ANSWER!
5. A person with a mass of 50 kg is moving at 4 m/s. How much
momentum does the person have?
Find:
Solution:
Given:
6.
His teammate has a mass of 40 kg is moving at 5 m/s. Who has more
momentum? Why?