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?

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?

Gravitational ForceThis is the force 2 objects feel towards each other

F = G mass1 x mass2

d2

G = 6.673 x 10-11 Nm2/kg2 -this is a constant

500 N 1000 N

2 meters

How much gravitational force is felt between the two?

The object Weight on earthAre given

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 = mgWhat 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)?

Apparent Weight

FN = mg + ma

Apparent Weight True Weight The accelerationthat is

happeningThis elevator has a total mass of 500 kgThe 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?

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

Friction

? N of Force

Wood Wood (Wet) 0.2Wood Metals(Clean) 0.2-0.6Wood Metals (Wet) 0.2Wood Brick 0.6Wood Concrete 0.62

Mass = 450 kg

Considering the situation above, the hot tub sitsOn 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 needTo push to keep the tub moving at a constant speed of 1 m/s?

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

Tension Force

The force applied to a rope or cable

-T T

Equilibrium

An object is in equilibrium when it has

ZERO ACCELERATION! L

T

R

W

An airplane is flying 200 mph at an angle of20o 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?