NEWTON’S LAWS OF MOTION

NEWTON’S LAWS OF MOTION

Three Laws that Explain How and Why Objects Move

NEWTON’S 1ST LAW OF MOTION

Law Of Inertia Inertia Is An Object’s Resistance To Motion

An Object At Rest Stays At Rest, And An Object In Motion Stays In Motion With The Same Velocity, Unless Acted Upon By An Outside Force

NEWTON’S 1ST LAW EXAMPLES

1st Law (2:40)

NEWTON’S 2ND LAW OF MOTION Acceleration is produced when a force acts on a mass.

The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object).

Heavier objects require more force to accelerate the same amount as lighter objects.

The object accelerates in the direction that you push it

If you push the object with twice as much force, it accelerates twice as much

If the object has twice the mass, it accelerates half as much (with the same force)

NEWTON’S 2ND LAW EXAMPLES

2nd Law (3:10)

NEWTON’S LAWS REVIEW! A space ship cruises through space with a constant

velocity without using any fuel. 1st Law

A soccer player kicks a ball with her foot and her toes are left stinging. 3rd Law

A golf ball will accelerate faster and go farther than a baseball if each are hit with the same amount of force. 2nd Law

A picture is hanging on a wall and does not move. 1st Law

Referred to as the law of inertia. 1st Law

A person’s body is thrown outward as a car rounds a curve on a highway. 1st Law

3rd

2nd1st

2nd

1st & 3rd

1st3rd

3rd

3rd2nd

1st3rd

2nd 3rd

3rd1st

2ND LAW FORMULAS AND UNITS 3 formulas

F=ma a=F/m m=F/a

Units Newton

1 N = about the weight of a small apple (102 g) The amount of force necessary to accelerate one

kilogram 1m/s2

Mass: kg Acceleration: m/s2

Force: kgm/s2 = N (Newtons) You must have kg and m/s2 To do these

problems! Convert if you have to!

NEWTON’S 2ND LAW PROBLEMS!1. You give a shopping cart a shove down

the street. The cart is full of puppies and has a mass of 18 kg. The cart accelerates at a rate of 3 m/s2. How much force did you exert on the cart?

F = ma F = 18 kg 3 m/s2

F = 54 kg m/s2

F = 54 N

2. You are super angry and throw a Barbie® Doll across the room with a force of 2N and it accelerates at 8 m/s2. What is the mass of the doll in grams?

M= M= M= M= kg or 0.25 kg M= 250 g

3. Last weekend, you decided to wander through the mountains. You come across a pack of sleeping coyotes. You decide to prank the largest coyote by yelling into its ear and running off. Behind you, you see the 30kg coyote chasing you as it exerts a force of 120 N. What is its acceleration?

A= A= A= A= 4 m/s2

2ND LAW CALCULATIONS: YOUR TURN! A 10 kg bowling ball would require what force to

accelerate it down an alley at a rate of 3.5 m/s2? F = ma F = 10kg 3.5 m/s2

F = 35 kg m/s2

F = 35 N What is the mass of a truck if it produces a

force of 14,000 N while accelerating at a rate of 5 m/s2? m = m = m = m = 2,800 kg

NEWTON’S 3RD LAW OF MOTION

For Every Action There is an Equal and Opposite Reaction

Forces Act in Pairs

NEWTON’S 3RD LAW EXAMPLES The rocket's action is to push down on the

ground with the force of its powerful engines, and the reaction is that the ground pushes the rocket upwards with an equal force.

3rd Law (2:50)

MORE VIDEOS

All Laws (4:30)

All Laws 2 (4:19)

All Laws 3 (3:40)