1. Q of the day?
A sailboat is motoring forward with a force of 50 N. The sails are providing a force of 100 N at 45o off the bow (nose of the boat). What is the total forward Force acting on the boat?
How much force is the boat going perpendicular to the bow?

2. Types of Forces 4 universal forces of the universe Gravitational
Nuclear Weak
Nuclear Strong
Electromagnetic
What force could be expanding the universe?
Perhaps there are more forces that are not yet discovered?

3. Gravitational Force d2 G = 6.673 x 10-11 Nm2/kg2 -this is a constant
This is the force 2 objects feel towards each other
F = G mass1 x mass2 d2
G = x Nm2/kg2 -this is a constant
2 meters
The object
Weight on earth
Are given
500 N
1000 N
How much gravitational force is felt between the two?

4. Normal Force
The force that a surface exerts on an object with which it is in contact (this force is perpendicular to the surface).
FN = mg
What is the normal force
Acting on the pot of
coffee (1 kg)?
How much normal force is
The floor acting on the table
(20 kg)?

5. Apparent Weight FN = mg + ma
Apparent Weight True Weight The acceleration that is happening
This elevator has a total mass of 500 kg
The elevator accelerates upward at .5 m/s2
What is the apparent weight of the elevator?
When the elevator is going up at a constant rate,
What is the apparent weight?
If the elevator cable snaps and falls towards earth,
What is the apparent weight?

6. Friction Static Friction – Friction of non-moving object fsMax = μsFN
Kinetic Friction – Friction on moving objects
fk= μkFN
μ (Meu) is the coefficient of friction, the unitless number is a representation of the contact points between surfaces

7. Friction Mass = 450 kg Wood Wood (Wet) 0.2 Wood Metals(Clean) 0.2-0.6
Wood Metals (Wet)
Wood Brick
Wood Concrete
Make money on Physics:
To make furniture move easier, place the legs on a material that will have a low Coefficient of Friction with the carpet
? N of Force
Considering the situation above, the hot tub sits
On a concrete slab and is being pushed by a gorilla.
How much force must the gorilla apply to set the hot
Tub in motion?
Once in motion, the kinetic c`oefficient of friction is
Reduced to .4. How much force does the gorilla need
To push to keep the tub moving at a constant speed of 1 m/s?

8. Tension Force
The force applied to a rope or cable
-T T

9. Equilibrium An object is in equilibrium when it has ZERO ACCELERATION!
An airplane is flying 200 mph at an angle of
20o above the surface. The plane has a mass of 5,000 kg and has a forward thrust of 100,000 N. What is the Force of Air Resistance and the Upward Lifting force of the wings?