Download 1 Newton`s Laws of Motion

Newton's Laws of Motion Date _______
Background Information
Aristotle believed that every object had a proper place and if it was not in that place it would move to get there like a rock falling to the ground.
Galileo experimented with dropped objects by first rolling the objects down inclined planes where he determined that objects moved in terms of rates of change: speed, velocity, and acceleration.
Isaac Newton refined Galileo's ideas into three important laws published in his famous book Principia
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Newton's Laws of Motion Date _______
Newton's First Law: The Law of Inertia
Inertia is the tendency of an object to resist
a change in motion. Remember a change in
motion is an __________________.
Newton's First Law: An object at __________ remains at _____ and an object moving at a__________ ___________ and continues at a ______________ ________________ unless acted on by an ________________ force.
In other words, an object continues to do whatever it is doing unless an _______________ force acts on it.
Why does the person above fly out of the car when the car hits the brick wall?
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Newton's Second Law: Net Force related to Mass and Acceleration
The acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to the object's mass.
In equation form: Net Force = mass x acceleration
F = ma
Newton's Third Law: Force Pairs
If two objects interact, the magnitude of the force exerted on object 1 by object 2 is equal to the magnitude of the force simultaneously exerted on object 2 by object 1, and these two forces are opposite in direction. 3
Mass is a measure of inertia
There is a basketball and a bowling ball on the ground. From Newton's First Law we know that they will both remain at REST until acted on by an unbalanced force.
If they are both acted on by equal forces, which one will accelerate more?
Why?
Mass, which is the measure of the amount of matter in an object, is also a measure of the inertia of the object.
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Imagine a place in the cosmos far from all gravitational and frictional influences. Suppose that you visit that place (just suppose) and you throw a rock. What will happen to the rock?
Why?
A 2­kg object is moving horizontally with a speed of 4 m/s. How much net force is required to keep the object moving at this speed and in this direction?
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Supposing you were in space in a weightless environment, would it require a force to set an object in motion?
A feather and an elephant are in outer space. Which would be harder
to move? Why?
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Centripetal Force and Centripetal Acceleration
An accelerating object is an object that is changing its velocity. And since velocity is a vector that has both magnitude and direction, a change in either the magnitude or the direction results in a change in the velocity. An object moving in a circle at constant speed is indeed accelerating. It is accelerating because the direction of the velocity vector is changing.
The acceleration of the object is directed towards point C, the center of the circle. This is called centripetal acceleration.
Objects moving in circles at a constant speed accelerate towards the center of the circle.
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There is an inward­directed acceleration that demands an inward force. Without this inward force, an object would maintain a straight­line motion along the perimeter of the circle. Without this inward or centripetal force, circular motion would be impossible.
Without a centripetal force, an object in motion continues along a straight­line path.
With a centripetal force, an object in motion will be accelerated and change its direction.
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Demo Name
Unbalanced force acts on
Explain the demo using Newton's Laws
Demo Name
Unbalanced force acts on
Explain the demo using Newton's Laws
Demo Name
Unbalanced force acts on
Explain the demo using Newton's Laws
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