AP Physics Momentum Review

Momentum - the product of an object’s mass and velocity. The more momentum an object has, the harder (more force) to bring it to rest. 

p - momentum (kg m/s) 

m - mass  (kg) 

v - velocity (m/s)

Multiple Choice

What is p in equation p = mv

• power

• momentum

• mass

• velocity

​Total Momentum

​Each object in the system has its own momentum, the sum of each object’s momentum is equal to the total momentum of the system

Open Ended

How would you find total momentum of the system?

Conservation of momentum

​Conservation of Momentum: 

The total momentum in a system will remain the same when two objects interact as long as there is no outside forces acting on the system. 

The change in momentum of one object is balanced by the change in momentum of the other object so the total momentum remains constant. 

mA.vAi + mB.vBi = mA.vAf + mB.vBf

Multiple Choice

Total momentum of the system is always conserved

• True

• False

Multiple Choice

Momentum of each object is always conserved

• True

• False

Open Ended

Explain all the variables in equation

$$m_{A_{ }}v_{Ai}+m_Bv_{Bi}\ =\ m_Av_{Af}+m_Bv_{Bf}$$  

Multiple Choice

If two objects stick together after collision, then their final velocity must be

• zero

• same

Multiple Choice

To calculate impulse, you calculate

• momentum

• change in momentum

• velocity

• mass

Multiple Select

Equation for change in momentum is...

Select all that apply

• p = mv

• $$\Delta p\ =\ m\Delta v$$  

• $$\Delta p\ =\ F\Delta t$$  

• $$\Delta p\ =\ p_f-p_i$$  

Multiple Select

Equation for Impulse is...

Select all that apply

• I = mv

• $$I\ =\ m\Delta v$$  

• $$I=\ F\Delta t$$  

• $$I\ =\ p_f-p_i$$  

Poll

How prepared do you feel after this review

• Well prepared

• prepared

• somewhat prepared

• not at all

Multiple Choice

Read the following and discuss with your partner. If your partner is not up to that slide then wait for your partner to finish previous slides. Discuss it with your partner and select a skill below that you need for this concept. Select all that apply.

Mass and Velocity are the two variables that determine the amount of momentum. So large objects moving fast have the most momentum. 

• Be able to calculate the momentum of an object using the equation p = mv 

• Be able to identify the objects interacting in a system

• 1)Be able to calculate the total momentum of the objects in a system  ptotal = pA + pB  

  2)Apply the conservation of momentum principle to calculate velocity of objects before or after collisions.

• Be able to calculate the change in momentum  Δp = m Δv  or Δp = pf - pi 

• Be able to calculate the impulse an object experiences Impulse = Ft 

Multiple Choice

Read the following and discuss with your partner. If your partner is not up to that slide then wait for your partner to finish previous slides. Discuss it with your partner and select a skill below that you need for this concept. Select all that apply.

The total momentum in a system is the sum of each object’s momentum.  Momentum is a vector so positive and negative (direction) is important. 

• Be able to calculate the momentum of an object using the equation p = mv 

• Be able to identify the objects interacting in a system

• 1)Be able to calculate the total momentum of the objects in a system  ptotal = pA + pB  

  2)Apply the conservation of momentum principle to calculate velocity of objects before or after collisions.

• Be able to calculate the change in momentum  Δp = m Δv  or Δp = pf - pi 

• Be able to calculate the impulse an object experiences Impulse = Ft 

Multiple Choice

Read the following and discuss with your partner. If your partner is not up to that slide then wait for your partner to finish previous slides. Discuss it with your partner and select a skill below that you need for this concept. Select all that apply.

Momentum is directly proportional to both mass and velocity 

• Be able to calculate the momentum of an object using the equation p = mv 

• Be able to identify the objects interacting in a system

• 1)Be able to calculate the total momentum of the objects in a system  ptotal = pA + pB  

  2)Apply the conservation of momentum principle to calculate velocity of objects before or after collisions.

• Be able to calculate the change in momentum  Δp = m Δv  or Δp = pf - pi 

• Be able to calculate the impulse an object experiences Impulse = Ft 

Multiple Choice

Read the following and discuss with your partner. If your partner is not up to that slide then wait for your partner to finish previous slides. Discuss it with your partner and select a skill below that you need for this concept. Select all that apply.

Objects that are connected, stuck together, or attached will have the same velocity 

• Be able to calculate the momentum of an object using the equation p = mv 

• Be able to identify the objects interacting in a system

• 1)Be able to calculate the total momentum of the objects in a system  ptotal = pA + pB  

  2)Apply the conservation of momentum principle to calculate velocity of objects before or after collisions.

• Be able to calculate the change in momentum  Δp = m Δv  or Δp = pf - pi 

• Be able to calculate the impulse an object experiences Impulse = Ft 

Multiple Choice

Read the following and discuss with your partner. If your partner is not up to that slide then wait for your partner to finish previous slides. Discuss it with your partner and select a skill below that you need for this concept. Select all that apply.

When objects originally have zero momentum and then push off each other, they end up with the same momentum in opposite directions in order to conserve their zero total momentum. 

• Be able to calculate the momentum of an object using the equation p = mv 

• Be able to identify the objects interacting in a system

• 1)Be able to calculate the total momentum of the objects in a system  ptotal = pA + pB  

  2)Apply the conservation of momentum principle to calculate velocity of objects before or after collisions.

• Be able to calculate the change in momentum  Δp = m Δv  or Δp = pf - pi 

• Be able to calculate the impulse an object experiences Impulse = Ft 

Multiple Select

Read the following and discuss with your partner. If your partner is not up to that slide then wait for your partner to finish previous slides. Discuss it with your partner and select a skill below that you need for this concept. Select all that apply.

1) An impulse is equal to a change in momentum and is caused by a force acting during a period of time. 

2)When two isolated objects interact, the change in momentum (impulse) of one object will be equal but opposite to the change in momentum (impulse) of the second object.  

3)When two objects interact, the total momentum before their interaction has to be the same as their total momentum after their interaction. 

• Be able to calculate the momentum of an object using the equation p = mv 

• Be able to identify the objects interacting in a system

• 1)Be able to calculate the total momentum of the objects in a system  ptotal = pA + pB  

  2)Apply the conservation of momentum principle to calculate velocity of objects before or after collisions.

• Be able to calculate the change in momentum  Δp = m Δv  or Δp = pf - pi 

• Be able to calculate the impulse an object experiences Impulse = Ft 

Multiple Choice

Read the following and discuss with your partner. If your partner is not up to that slide then wait for your partner to finish previous slides. Discuss it with your partner and select a skill below that you need for this concept. Select all that apply.

The change in a variable is the final value minus the initial value

• Be able to calculate the momentum of an object using the equation p = mv 

• Be able to identify the objects interacting in a system

• 1)Be able to calculate the total momentum of the objects in a system  ptotal = pA + pB  

  2)Apply the conservation of momentum principle to calculate velocity of objects before or after collisions.

• Be able to calculate the change in momentum  Δp = m Δv  or Δp = pf - pi 

• Be able to calculate the impulse an object experiences Impulse = Ft