FORCE
Force
A push
or pull
one thing exerts on
another
What do you know?
(Examples, pictures, definitions, experiences)
Normal
Force
Tension
Weight
Applied
Force
Friction
Air
resistance
Which of the following would be
a unit that measures force?
1.
2.
3.
4.
kilograms
ounces
pounds
meters per second
Units of force
• English system
• Metric system
– Pounds (lbs.)
– Newtons (N)
Quarter pounder
0.22 pounds = 1 Newton
What force is acting up on the
skydivers?
1.
2.
3.
4.
Normal force
Weight
Tension
Air resistance
What force is acting down on
the skydivers?
1.
2.
3.
4.
Normal force
Weight
Tension
Friction
What are the two forces acting on these skydivers?
Air resistance
Weight (force because of gravity)
What is the name of the upward
force that the table is supplying to
the cell phone pictured below?
1.
2.
3.
4.
5.
Weight
Friction
Tension
Normal
Air resistance
What are the two forces acting on this cell phone?
Normal Force
Weight (force because of gravity)
What are the other two forces acting on the truck?
Friction
Applied Force
What is the name
of the force drawn
in the picture?
1.
2.
3.
4.
5.
6.
Air resistance
Weight
Tension
Friction
Normal Force
Applied Force
17%
1
17%
2
17%
17%
3
4
17%
5
17%
6
When I hit the brakes in a car, the car
comes to a stop because _______ acts
between the tires and the road.
17%
1.
2.
3.
4.
5.
6.
17%
17%
17%
3
4
17%
17%
Air resistance
Weight
Tension
Friction
Normal Force
Applied Force
1
2
5
6
Balanced Forces
5N
5N
When forces are equal in size and opposite in direction.
Unbalanced Forces
45 N
15 N
Forces that are not equal in size OR
Unbalanced Forces
Forces that are not opposite in direction.
Net Force
The overall force acting on an object.
Who’s winning and by how much?
Net Force
12 N
20 N
4N
Net force = 16 N
12 N
What is the magnitude of the
net force acting on the object?
20 N
10 N
10 N
12 N
What is the direction of the net
force acting on the object?
1.
2.
3.
4.
up
down
left
right
20 N
10 N
10 N
12 N
Force vectors
When adding vectors, you can move them, but
you can’t change the size or direction
4N
3N
Given the following picture, how
would you describe the weight and
normal force?
1. Balanced
2. Unbalanced
50%
1
50%
2
Examples in SMART