Essential Questions Who discovered the Three Laws of Motion? What is Newton’s Second Law & how does it apply to motion?

Newton’s First Law “An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an unbalanced force.”

More Laws of Motion Newton’s First Law of Motion states that if you kick a ball, the ball will move. Newton’s Second Law of Motion says that when a force acts on an object, the object accelerates. –If you kick the ball harder, it will move faster. –It also tells you that a heavy ball is harder to move than a lighter ball.

Newton’s Second Law Force equals mass times acceleration. F = ma Acceleration: a measurement of how quickly an object is changing speed. (Acceleration occurs when an object speeds up, slows down, or changes its direction of motion... ANY CHANGE IN MOTION IS ACCELERATION) Mass: the amount of matter in an object

NEWTON’S SECOND LAW The more force that is applied, the more the object will accelerate.

NEWTON’S SECOND LAW The object will accelerate in the direction of the force.

Newton’s Second Law of Motion A long row of shopping carts takes more force to move than one empty cart requires. Takes more force to move

NEWTON’S SECOND LAW The more mass an object has, the harder it is to accelerate. The less mass an object has, the easier it is to accelerate. This truck takes more to accelerate because it has a lot of mass.

Let’s Look at it This Way.. A car will stop suddenly if the driver slams on the brakes. However, if the driver applies the brakes gently, the car gradually slows down.

What does F =MA mean? Force is directly proportional to mass and acceleration. Imagine a ball of a certain mass moving at a certain acceleration. This ball has a certain force. Now imagine we make the ball twice as big (double the mass) but keep the acceleration constant. F = ma says that this new ball has twice the force of the old ball. Now imagine the original ball moving at twice the original acceleration. F = ma says that the ball will again have twice the force of the ball at the original acceleration.

What does F = ma say? F = ma basically means that the force of an object comes from its mass and its acceleration. Something very small (low mass) that’s changing speed very quickly (high acceleration), like a baseball, can still have a great force. Something very small changing speed very slowly will have a very weak force. Something very massive (high mass) that’s changing speed very slowly (low acceleration), like a glacier, can still have great force.

Let’s Review What is the effect of a car’s acceleration if six people ride in the car instead of one?

Let’s Review Acceleration is produced by _________. –A.) masses –B.) forces –C.) velocity –D.) pressure

Let’s Review True or False If… Force = mass x acceleration Then… Acceleration = force / mass (net force)

Acceleration… Remember our question from the beginning of class? If someone told you that a car was accelerating, what would that mean to you? What would you say now?

How is slowing down acceleration? Acceleration in the same direction as velocity speeds up an object. Acceleration directed opposite of velocity slows down an object. Acceleration on an object with zero velocity makes the object START to move in the direction of the acceleration.

Newton’s 2 nd Law Centers Station 1:  Eraser Racers Station 2:  Speed Racers Station 3:  Weighty Situation Station 4:  Speeding Train Station 5:  Explaining Newton’s Laws Station 6:  Taking notes