1. newton’s laws of motion
Newton’s 3rd Law
”For every action, there’s an equal and opposite reaction.”
All forces act in pairs.

2. newton’s laws of motion
This means every time a force is applied in one direction an equal force is applied in the opposite direction.
If you push against a wall it pushes back
These forces can cause motion, like a swimmer
They do not cancel each other out because they act on different objects.
If an object is not in motion, then all forces acting on it are balanced and the net force is zero!

3. newton’s laws of motion
Which of the following scenarios does NOT represent Newton’s 3rd Law?
A rocket being launched into space.
A book resting on a desk.
A person paddling a canoe.
A large force pushing on a small mass, causing it to accelerate.

4. newton’s laws of motion
Which of the following scenarios does NOT represent Newton’s 3rd Law?
A rocket being launched into space.
A book resting on a desk.
A person paddling a canoe.
A large force pushing on a small mass, causing it to accelerate.

5. MOmentum Newton’s 3rd Law also deals with momentum
Momentum is a property of a moving object.
Influences how easily an object can be stopped
Momentum depends on the objects mass and velocity.
If a small car and a large truck are both traveling down the highway at the same velocity, the truck has more mass, therefore it will have more momentum.

6. Momentum High velocity or high mass cause a high momentum
For some reason, maybe because mass is designated as “m” in formulas, momentum is designated as “p”.
The product of an object’s mass x velocity
Therefore: p = mv
The unit for mass is kg, the unit for velocity is m/s, therefore the unit for momentum is kgm/s

7. which has more momentum?
...a kg golf ball with a speed of 60.0 m/s?
...a 7.0 kg bowling ball with a speed of 6.0 m/s?

8. which has more momentum?
...a kg golf ball with a speed of 60.0 m/s?
...a 7.0 kg bowling ball with a speed of 6.0 m/s?

9. CONSERVATION OF momentum
Conservation of Momentum: When a moving object hits another object, the momentum of the first object transfers to the second object.
Momentum is Conserved
pbefore = pafter ...so therefore m1v1 = m2v2
If no net force acts on a system, then the total momentum of the system does not change
In a closed system, loss of momentum of one object equals the gain in momentum of another object

10. Conservation of momentum
Example:
When one pool ball hits another pool ball on a pool table, the momentum of the first ball is transferred to the second ball as it hits.

11. momentum scenario #1
2 moving objects: During this collision the speed of both box cars changes. The total momentum remains constant before & after the collision. The masses of both cars is the same so the velocity of the red car is transferred to the blue car.
Sketch in pictures & Equations into notes.

12. momentum scenario #2
1 moving object: During this collision the speed red car is transferred to the blue car. The total momentum remains constant before & after the collision. The masses of both cars is the same so the velocity of the red car is transferred to the blue car.
Sketch in pictures & Equations into notes.

13. momentum scenario # 3
2 connected objects: After this collision, the coupled cars make one object w/ a total mass of 60,000 kg. Since the momentum after the collision must equal the momentum before, the velocity must change. In this case the velocity is reduced from 10 m/sec. to 5 m/sec.
Sketch in pictures & Equations into notes.