1. Newton’s 2nd Law of Motion

2. Objective 8
Level 3
Students will understand the relationship between mass, net force and acceleration and can use this understanding to predict the behavior of an object under the influence of one or several forces.
Level 2
Can recall Newton’s 2nd Law.
General understanding of relationship between net force / mass and acceleration.

3. Acceleration- change in velocity over time
Change the speed or direction
How do we do this??

4. Acceleration is caused by a FORCE
Acceleration is always in the same direction of the net force

5. Acceleration and Force are Directly Proportional!
Directly Proportional- what ever one quantity does, the other one does the same!
Double the force, I _________ the acceleration
Half the force, I __________ the acceleration

6. Acceleration also depends on mass
Acceleration is inversely proportionate to mass
I double the mass, I _________ the acceleration

7. More mass an object has the less acceleration
Acceleration ~1/ mass
Acceleration is inversely proportionate to mass

8. Newton’s 2nd law
The acceleration produced by a net force on an object is directly proportional to the net force, is in the same direction as the net force and is inversely proportional to the mass of an object
F=ma

9. In other words: The larger the net force, the bigger the acceleration.
Acceleration and net force are always in the same direction.
The larger the mass the smaller the acceleration.

10. Practice Problems
Consider a 1000kg car pulled by a cable with 2000N of force. What would be the acceleration?

11. One more problem
If a mass of 5kg is moving at an acceleration of 3 m/s2, what is the force?