1. Momentum Objectives (Mom. and Energy Unit)
Define and calculate the momentum of an object. 
Determine the impulse given to an object. 
Interpret and use force vs. time graphs (Base x Height). 
Apply conservation of momentum to solve a variety of problems. 
Distinguish between elastic and inelastic collisions. 

2. Example 2
On a snow-covered road, a car with a mass of 1100 kg collides head- on with a van having a mass of 2500 kg traveling at 8 m/s. As a result of the collision, the vehicles lock together and immediately come to rest. Calculate the speed of the car immediately before the collisions. [Neglect friction]

3. On a snow-covered road, a car with a mass of 1100 kg collides head-on with a van having a mass of 2500 kg traveling at 8 m/s. As a result of the collision, the vehicles lock together and immediately come to rest. Calculate the speed of the car immediately before the collisions. [Neglect friction]
Pbefore (kg*m/s)
Pafter (kg*m/s)
Car
Van
Total

4. Car 1100*Vcar = 1100Vcar Van 2500*(-8) = -20,000 Total
On a snow-covered road, a car with a mass of 1100 kg collides head-on with a van having a mass of 2500 kg traveling at 8 m/s. As a result of the collision, the vehicles lock together and immediately come to rest. Calculate the speed of the car immediately before the collisions. [Neglect friction]
Pbefore (kg*m/s)
Pafter (kg*m/s)
Car
1100*Vcar = 1100Vcar
Van
2500*(-8) = -20,000
Total
1100Vcar – 20,000

5. Car 1100*Vcar = 1100Vcar Van 2500*(-8) = -20,000 Total
On a snow-covered road, a car with a mass of 1100 kg collides head-on with a van having a mass of 2500 kg traveling at 8 m/s. As a result of the collision, the vehicles lock together and immediately come to rest. Calculate the speed of the car immediately before the collisions. [Neglect friction]
Pbefore (kg*m/s)
Pafter (kg*m/s)
Car
1100*Vcar = 1100Vcar
Van
2500*(-8) = -20,000
Total
1100Vcar – 20,000

6. Car 1100*Vcar = 1100Vcar Mv = (1100+2500)(0) = 0 Van
On a snow-covered road, a car with a mass of 1100 kg collides head-on with a van having a mass of 2500 kg traveling at 8 m/s. As a result of the collision, the vehicles lock together and immediately come to rest. Calculate the speed of the car immediately before the collisions. [Neglect friction]
Pbefore (kg*m/s)
Pafter (kg*m/s)
Car
1100*Vcar = 1100Vcar
Mv = ( )(0) = 0
Van
2500*(-8) = -20,000
Total
1100Vcar – 20,000

7. Example 3
A 4-kg rifle fires a 0.02-kg shell with a velocity of 300 m/s. Find the recoil velocity of the rifle.

8. A 4-kg rifle fires a 0. 02-kg shell with a velocity of 300 m/s
A 4-kg rifle fires a 0.02-kg shell with a velocity of 300 m/s. Find the recoil velocity of the rifle.
Pbefore (kg*m/s)
Pafter (kg*m/s)
Rifle
Shell
Total

9. A 4-kg rifle fires a 0. 02-kg shell with a velocity of 300 m/s
A 4-kg rifle fires a 0.02-kg shell with a velocity of 300 m/s. Find the recoil velocity of the rifle.
Pbefore (kg*m/s)
Pafter (kg*m/s)
Rifle
Shell
Total

10. A 4-kg rifle fires a 0. 02-kg shell with a velocity of 300 m/s
A 4-kg rifle fires a 0.02-kg shell with a velocity of 300 m/s. Find the recoil velocity of the rifle.
Pbefore (kg*m/s)
Pafter (kg*m/s)
Rifle
Mv = (4+0.02)(0) = 0
Shell
Total

11. A 4-kg rifle fires a 0. 02-kg shell with a velocity of 300 m/s
A 4-kg rifle fires a 0.02-kg shell with a velocity of 300 m/s. Find the recoil velocity of the rifle.
Pbefore (kg*m/s)
Pafter (kg*m/s)
Rifle
4*Vrecoil
Shell
(.02)(300) = 6
Total
6 + 4Vrecoil

12. Questions to go over
Conceptual: 7
Calculation: 9, 16