1. Newton’s Laws of Motion
J. Sebastian Oddone
District Supervisor

2. Objectives The objectives of this lesson are to understand:
What is a force?, specifically Gravitational force
Review of Newton’s Laws of Motion
The relation between force and motion

3. SC.C The student knows that the motion of an object is determined by the overall effect of all the forces acting on the object. (Assesses C and C.2.2.3)

4. Newton’s III Laws of Motion:
Law of Inertia: An object at rest will remain at rest unless acted upon by an external and unbalanced force. An object in motion will remain in motion unless acted upon by an external and unbalanced force.
Law of Acceleration: The rate of change of momentum of a body is proportional to the resultant force acting on the body and is in the same direction.
Law of Reciprocal Action: All forces occur in pairs, and these two forces are equal in magnitude and opposite in direction.

5. 1st Law: Block on a frictionless surface
An external force caused the block to move.
In this case the block is at rest and would stay at rest, but…

6. 1st Law: Block on a surface (with Friction)
In this case two external forces act on the box, the hand and the friction on the surface. One force makes the block move, while the other force causes the block to stop

7. = F ma m 2nd Law: Block on a frictionless surface
In this case the block is at rest and would stay at rest, but a force causes the mass to accelerate in the direction of the applied force

8. 3rd Law: Block on a table on the Earth
Contact forces (Electromagnetic Fields)
Field forces (Gravitational) m
Earth

9. FT/B FG/T FB/T FT/G 3rd Law: Block on a table on the Earth
Contact Forces
Table
Box
Ground
FT/B m
FG/T
FB/T
FT/G
Earth

10. FB/E FT/E FE/B FE/T 3rd Law: Block on a table on the Earth
Gravitational Field Forces
Table
Box
Earth
FB/E m
FT/E
FE/B
Is there a gravitational force between the box and the table?
Since both objects have mass, the answer is yes. The box has a gravitational force pulling on the table, and the table has a gravitational force pulling on the box.
FE/T
Earth