This document defines and describes various types of forces including contact forces, non-contact forces, gravity, and net force. It explains that a force is a push or pull on an object that can cause it to start, stop, or change motion. Forces are described by their strength and direction. The SI unit for force is the Newton, and one Newton is approximately the force needed to lift a lime. Forces can be contact forces like friction or non-contact forces like gravity and magnetism. Gravity is the attractive force between all objects with mass. Weight and mass are related but different, as weight can change with gravity but mass does not. Net force is calculated by adding or subtracting forces based on their direction.

3.  A push or pull on an object.
 Described by:
•STRENGTH
•DIRECTION
 A force gives an object energy to:
•STOP MOVING
•START MOVING
•CHANGE DIRECTION

4.  The SI unit for force is the
 The symbol for Newton is
 One Newton = about the force you exert to
lift a lime.
 Named after:
NEWTON
N
Sir Isaac Newton (founder of
physics)

5.  Contact Force
 Non Contact Force

6.  A push or pull on one object by another that
is touching it.
 Contact forces can be:
 Strong
OR
 Weak
Example:
FRICTION= force that opposes
motion between two surfaces in
contact.

7.  A force that one object can apply to another
object without touching it.
 Examples Include:
 Gravity- universal attraction between all objects.
 Magnetism- attracts and repels objects

8.  An attractive force that exists between all objects that
have mass.
◦ Weight is a measure of the force of gravity acting upon an
object.
 On EARTH the force of gravity = 9.8 m/s2
 All objects fall to the Earth at an acceleration
of 9.8m/s2 due to the force of gravity.

9.  The amount of matter in an object.

10.  Weight and mass are related, but ARE NOT the
same.
CHANGE GRAVITY
 Weight can due to
 Mass change
DOES NOT

11.  can be used to show forces.
ARROWS
LENGTH
 The of an arrow shows the
of the force.
STRENGTH
DIRECTION
 The that the arrow points
shows the direction in which the
FORCE WAS
APPLIED
LONGER
 The stronger the force the the
arrow.

12.  The combination of all the forces acting on an
object.
 To calculate the net force:
◦ If the forces act in the same direction they are
added together.
◦ If forces act in opposite directions they are
subtracted.
DO THE MATH pg 191, #13. Do with shoulder partner.

13.  Forces acting on an object that combine and
form a net force of ZERO. NO change in
motion.

14.  Forces acting on an object that combine and
form a net force that is not zero.
 Unbalanced forces cause an object to move.
 Forces moving in the same direction are
ADDED
 Forces moving in the opposite direction are
SUBTRACTED

15. FORCE= MASS x ACCELERATION
F= ma
Force measured in NEWTONS
Mass measured in KILOGRAMS
Acceleration measured in M/S2
DO THE MATH pg 195….RACE!

16.  Weight and mass are related, but ARE NOT the same.
 Weight can due to
CHANGE GRAVITY
 Mass change
DOES NOT
F =
Weight on Earth =
M x A
MASS x 9.8m/s2 (acceleration
due to the force of gravity)