Chapter 5: Momentum Flashcards
State the equation to calculate momentum
p = mv
where
p is momentum in kg m/s
m is mass in kg
v is velocity in m/s
State the MKS unit for momentum.
kg m/s
What is the momentum of a 1kg object moving at 1 m/s?
p = mv
p= (1kg) (1m/s) = 1 kg m/s
What is the momentum of a 2kg object moving at 5 m/s?
p = mv
p= (2kg) (5m/s) = 10 kg m/s
What is the momentum of a 7kg object moving at 3 m/s?
p = mv
p= (7kg) (3m/s) = 21 kg m/s
Solve the momentum equation (p=mv) for velocity.
p/m= v (divide both sides by m)
Solve the momentum equation(p=mv) for mass.
p/v = m (divide both sides by v)
State the law of the conservation of momentum.
In any interaction, the total momentum of the objects involved is conserved.
Define elastic collision.
Objects bounce perfectly apart without damage and kinetic energy is conserved.
Define inelastic collision.
The kinetic energy of the moving objects is not conserved. Kinetic energy is converted to heat, sound or used to deform the objects.
Describe what happens when an moving object collides with a stationary object and the masses are equal.
The moving object stops dead, and the stationary object moves with the same velocity and direction.
Describe what happens when a large mass collides with a small mass at rest.
both masses move off in the original direction of motion.
Describe what happens when a small mass collides with a large mass at rest.
the small mass bounces back (negative velocity), while the large mass moves off in the original direction of motion.
State the equation for the conservation of momentum for an interaction between two objects where one starts at rest.
p1i =p1f +p2f
where
p1i is the momentum of the moving object before the collision (object 1) = m1v1i
p1f = momentum of object 1 after the collision= m1v1f
p2f = momentum of object 2 after the collision =m2v2f
If a 1kg ball going at 1 m/s hits a 1 kg ball at rest, what are the velocitities of the two balls after the collision?
v1f = 0
v2f = 1 m/s
