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SFS SC CH11#1
Newton's First Law of Motion
Question | Answer |
---|---|
law | a statement that describes events or relationships that exist in nature or relationships that exist in nature |
Sir Isaac Newton | during the 1600's the English scientist ---- suggested three laws of motion |
First Law | Newton's ---- all objects resist change in motion |
rest | Newton's first law means that an object at ---stays at unless an unbalanced force acts on it |
contines | Newton's first law means that an object in motion ----- moving in a straight line at a constant speed unless na unbalanced force acts on it |
inertia | ----- the tendency of an object to resist any change in its state of motion |
mass | the greater the ----- of an object, the more inertia the object has |
friction | a force between surfaces that resists the movement of one surface past the other surface |
energy | friction converts ----- of motion into thermal energy |
helpful or harmful | friction can be ----- or ----- |
control | without friction, motion would be very difficult to control |
moving , slow | without friction your would not be able to start ---- or if moving, ------ down |
reduce | wheels ----- friction becasue the rolling wheel and the surface it contacts peel apart rather than scrape against each other |
air resistance | the friction from air molecules hitting an object as the object moves through the air |
unbalanced | an ----- force can keep an object moving in a circle |
orbit | an example of circular motion is when the force of gravity keeps a satellite in ---- around the earth |
gravity | without -----, a satellite would fly off in a straight line |
Newton's 2nd Law | when a force is applied to an object it causes the object to acceleate |
mass | force = ----- x acceleration |
direction | an object accelerates in the ------ of the force that acts on it |
changes | when the acceleration of an object changes, the force acting on the object also is changing |
Galileo | the Italian scientist ----- showed that falling objects with different masses have the same acceleration. |
air | Galeileo's observation is sture unless the objects are affected by ----- resistance |
resistance | air ------ causes a parachute to slow down the descent of a skydiver |
streamline | a ---- object has a shape that reduces air resistance |
aircraft | ----- have a streamline design |
ships, submarines | streamlining is also helpful for objects that travel through water, such as ---- and ----- |
easily | fish and marine mammals are streamlined to move through water ------ |
pairs | all forces come in pairs |
Newton's 3rd Law | when one object exerts a force upon a second object, the second object exerts an equal and opposite force upon the first object |
action , reaction | Newton's third law also called the law of ---- and ----- |
equal , opposite | according to 3rd: as a person walks, his foot pushes on the ground, but the ground pushes back with an ---- and ----- force |