Newton’s Laws of Motion Notes Isaac Newton is the scientist who discovered the Laws of Motion. Balanced forces are forces that cancel each other out, so there is no movement of the object. Unbalanced forces occur when one force is stronger than another, which causes the object to move. Law Definition In other words….. Examples 1st an object in If something is Golf ball on a tee won’t move Law of moving, it will until it gets hit. will stay in motion continue to move; if motion, and an object at Inertia something is not Once it is in the air, it won’t stop rest will stay at rest moving, it will not until gravity pulls it down and unless a force acts on move UNLESS friction makes it stop. the object something changes that. 2nd The heavier Force = mass x acceleration Law of something is the , mass, and Force harder it is to move; The heavier the shopping cart, the acceleration are related. More force makes more force it takes to move it; the Acceleration If force increases, something move lighter the shopping cart, the less acceleration faster. force it takes to move it. increases. If mass increases, acceleration Examples: The more force used, the more the A bowling ball takes object accelerates, the less force decreases. more force to push used the less force the object than a beach ball. accelerates. 3rd For every action, there If you apply a force Action force: air rushes down Law of on something, it acts is an and equal back in the opposite Action / opposite reaction. direction and with the same amount of Reaction or force. Interaction Reaction force: balloon goes up Force = Mass x Acceleration: 1. m = 2 kg; a = 15 m/s2 2. m = 1000kg; a = 9.8 m/s2 3. f = 20 N; m = 10 kg f = ma f = ma a = f/m f = 2kg x 15 m/s2 f = 1000 kg x 9.8 m/s2 a = 20 N / 10 kg f = 30 N f = 9,800 N a = 2 m/s2 Net Force Practice: 1. In which direction and force will the car move? ____3 N ______ 10 N - 7 N 3 N 2. The dog on the left is pulling with 10 N and the dog on the right is pulling with 12 N. In which direction and force will the dogs/rope move? ________________ 12 N 2 N - 10 N 2 N 400 N 350 N 3. In which direction and force will the people/rope move? ________________ 320 N 20 N - 300 N 20 N 4. In which direction and force will the boxes move? ________________ 80 N 40 N - 40 N 40 N 5. The girl is pushing the piano with a force of 25 N. The boy is pulling the piano with a force of 20 N. In which direction and force will the piano move? __________________ 25 N + 20 N 45 N 45 N .