Transcript MOTION
NEWTON’S FIRST LAW OF MOTION By Stacie Green We know that “motion” is any object that is moving. We know that we describe motion in 3 ways: ◦ HOW it moved ◦ The DIRECTION it moved ◦ The SPEED it moved To move something, a “force” has to happen. A FORCE is a push or a pull To get a toy car to move, the force of pushing is applied as we push it across the floor. We can get it to move, but now how do we get it to stop? An object will stop when it loses speed or “momentum.” An object will stop when a “force” acts and stops it. Our toy car stops when it runs into the wall. What else makes something stop… • • We know that friction can help objects stop. Friction is when 2 objects rub together. • Friction can help you-tennis shoes on the gym floor so you have grip and won’t fall down. • Friction can hurt you-sock feet on the dance floor and you slide into a wall. The friction from the carpet and wheels on the toy car help it lose speed, slow down, and stop. An object is at rest when it is still. A force is still acting on the object to keep it still and keep it in place. GRAVITY Gravity pulls objects DOWN. Gravity is what keeps you in your seat, brings your ball back down, and you back down after you jump. We know how something moves and how something stops. We know that a force is a push or pull that makes things move. We know friction is 2 objects rubbing We know gravity pulls/pushes everything There’s more to motion-Let’s find out… together. back down. You have a hockey puck It is not moving, it is at rest To get the puck to move, you have to do something to the puck like hit it. This is the force. Without the force, it will stay in the same spot and be at rest. Watch this to learn more! ..\Desktop\Newton_s_First_Law_of_Motion.as f “An object at rest remains at rest unless acted on by another force.” An object will stay at rest or “look still” until you do something to make it move. The toy car stays at the starting line (at rest) until you push it (apply a force). The hockey puck sits on the ice (at rest) until you push it with the stick (apply a force). Think of a train-that train drives down a straight track and stays going in a straight direction. What happens when the track curves left or right? The train turns and goes left or right “An object in motion in a straight line tends to say in motion in a straight line unless acted upon by another force.” An object will go straight until a force makes it go another direction. Your paper airplane flies straight until gravity pushes it down. Thomas drives straight until the driver makes it “turn” with the track. Let’s see what we’ve learned so far about motion! Give this quiz a try and test your motion knowledge! A. Any object that is moving. B. Any object that flies. C. Any object that drives on the road. D. Any object this is sitting still. You’re right! Motion is described as any object that is moving! Anything that is moving is in motion. We can say motion is any object that is moving. Try the question again!! A. A pull B. Turning the key C. Throwing it D. A push We have to “push” the toy car to put it into motion! You’ve really been paying attention!! Think about what we have to do to get that toy car moving. It won’t move by itself, we have to do something to get it to move. Our forces are push and pull, which one will make the car move forward? Go back and try it again!! A. Speed, how fast, and how far B. Speed or how fast or slow an object moves C. At rest or not at rest and the direction D. Speed, direction, and how it is moving We describe an object’s motion by saying how fast or slow it goes, the direction it goes in, and by saying “how” it is moving. Try another question! When an object is moving, we describe “how” it is moving, how fast or slow it is going, and the direction is it moving. Try the question again! A. When 2 objects rub together causing it to slow down or stop. B. A type of genre C. A force that makes things move D. A story you would write Friction is when 2 things rub together. Friction is one reason why things stop or slow down! Way to go!!! Friction is why you slide on your sock feet in the dance studio or slide on ice. Friction is why the marbles would spin in space, but not on the carpet. Friction is 2 things rubbing together. Try it again! A. Remain at rest until a force acts on it or something makes it move B. Start moving by itself C. Push or pull itself D. Be out of energy You’re Right! An object at rest will stay that way until a force acts on it. Your hockey puck stays still until you hit it with the stick! Let’s do another one! Think of your hockey puck When it is sitting on the ice, is it moving? Does it move by itself or do you have to hit it with your stick? Go back and try the question again! A. Gravity B. Friction C. No wind D. Poor design YES! The airplane lands because gravity is pushing it down! Keep at it! You’re doing a great job!! Gravity is the force that pulls everything down to Earth. Gravity will act on the paper airplane and push it down. Try the question again! A. It falls B. It stops moving C. Another force acts on the object and changes the direction. You’ve really got it!! Thomas stays straight until the driver turns him (force would be pushing) to curve with the track! Thomas the Train moves down the straight railroad track. He doesn’t turn to match the track on his own. A force is applied (the driver turning him) and makes him curve with the track. Go back and try it again! YOU DID IT!! You really know your stuff! You made it through with flying colors! No doubt you’ll do great on your paper assessment too!! Sounds are courtesy of Microsoft Clip Art Pictures courtesy of the following: Microsoft Clip Art, http://www.freefever.com/animatedgifs/cars. html, clipart-for-free.blogspot.com, Image.google.com, and Green family photos Video courtesy of Discovery Education