Newton's first law of motion is the law of inertia. Newton's first law of motion states in Newton's laws of motion -Wikipedia, the free encyclopedia, "A body at rest stays at rest, and a body in motion stays in motion, unless it is acted on by an external force." Newton's first law of inertia can explain the motion of a penny on a bus, an animal's motion attempting to escape a predator, and motion in a stopping vehicle.
If you were sitting on a bus with a penny in your hand and throw the penny straight up into the air; where do you think the penny would land? Well, it depends on the motion of the bus. If the bus's speed is constant, then the penny will land back in your hand. If the bus accelerates after you have thrown the penny straight up, then the penny will land in back of the bus. The reason for this is because initially when the penny was in your hand, it was considered part of the bus. So, the penny was traveling at the speed of the bus. Once, the penny is released into the air, it's is separate from the bus. So, if the bus accelerates, then the bus is traveling faster than the penny, and the penny will land in back of the bus. On the other hand, if the bus brakes while the penny is in the air, then the penny will land in front of the bus. This happens because when the bus brakes it slows down, while the penny in the air does not change speed in the forward direction, which by the way matches the speed of the bus before it braked. This is why the penny lands in front of the bus. The penny will keep doing what it is already doing unless a force acts on it. It experience minor air resistance, but that is it. The penny will continue to move forward, unless a force stops it. The bus will continue at the same speed unless a force acts on it. If the bus bakes, the force of friction causes the bus to slow. If the bus accelerates, the force of the wheels on the surface causes it to increase speed. So, objects keep doing what they are already doing unless a force changes their motion according to Newton's first law.
If you were sitting on a bus with a penny in your hand and throw the penny straight up into the air; where do you think the penny would land? Well, it depends on the motion of the bus. If the bus's speed is constant, then the penny will land back in your hand. If the bus accelerates after you have thrown the penny straight up, then the penny will land in back of the bus. The reason for this is because initially when the penny was in your hand, it was considered part of the bus. So, the penny was traveling at the speed of the bus. Once, the penny is released into the air, it's is separate from the bus. So, if the bus accelerates, then the bus is traveling faster than the penny, and the penny will land in back of the bus. On the other hand, if the bus brakes while the penny is in the air, then the penny will land in front of the bus. This happens because when the bus brakes it slows down, while the penny in the air does not change speed in the forward direction, which by the way matches the speed of the bus before it braked. This is why the penny lands in front of the bus. The penny will keep doing what it is already doing unless a force acts on it. It experience minor air resistance, but that is it. The penny will continue to move forward, unless a force stops it. The bus will continue at the same speed unless a force acts on it. If the bus bakes, the force of friction causes the bus to slow. If the bus accelerates, the force of the wheels on the surface causes it to increase speed. So, objects keep doing what they are already doing unless a force changes their motion according to Newton's first law.
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shannon
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(Guest)
12/21/2009
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steven
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(Guest)
12/21/2009
I like that very much. that was very smart.
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