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Chapter 13
Chapter 13
Chapter 13
Chapter 13
Chapter 13
100
What explains why a ball rolls faster and faster as it goes down a hill and then stops when it bumps into a tree?
What is Newton's laws of motion
100
What is a simple machine? give examples.
A machine with only a few parts like a wheel and axle, a pulley, an inclined plane or a lever.
100
What happens when equal forces act on an object in opposite directions at the same time?
The forces balance each other and the net force is zero. They do not change the way the object moves.
100
What type of machine uses a rope or cable that runs through a grooved wheel. It makes work easier by changing the direction of the force needed to do work - curtain rods and flagpoles are examples.
What is a Pulley
100
What is Newton's 3rd Law?
The Action - Reaction Law. When one object exerts a force on another object, the object also exerts a force back. Action-reaction forces are always equal and opposite and they always occur in pairs. This can be see everywhere. Like a person leaning against a wall and the wall pushing back so the person doesn't fall down.
200
What is Newton's 2nd Law of Motion?
It explains how acceleration, mass and net force are related. Net forces on an object can change an object's velocity by causing it to speed up, slow down or change direction. All of these changes can be called accelerations. The formula for this concept is Force = Mass x Acceleration. F = m x a
200
What happens to a moving object that is in equilibrium?
it will continue to move at that same speed in a straight line.
200
How can the formula for Newton's second law be written differently?
Yes. It depends on what you are trying to find out: For Force: F = m x a For Acceleration: a = F/m for Mass: m = F/a etc.
200
What does net force determine?
Whether an object will start moving, stop moving or change direction.
200
What is it when all forces acting on an object balance each other? What happens to that object?
Equilibrium. If the object is motionless, it will remain so.
300
Work is done when....._________
a force causes an object to move.
300
Can different forces act on an object at the same time?
Yes. They may act in different directions, some may be stronger than others. The combination is the net force on the object.
300
What is the tendency for an object to resist any change in motion?
What is Inertia. Objects with more mass have more inertia. Its harder to get a fat slob to move its sorry rear end than a skinny minny :)
300
Can the acceleration from a small force on a small object be the same as from a big force on a big object?
Yes.
300
What is Newton's first law of motion?
An object will remain in constant motion unless a net force acts on the object. A resting object will stay resting. A moving object will continue at that speed in a straight line.
400
What is a device that chanes the direction or the amount of force needed to do work.
What is a machine.
400
Which of Newton's Laws is demonstrated by a hammer pounding a nail into a board.
I don't really know, but I think maybe all three? You think about it and let me know.
400
Who was considered the most important scientist of all time?
Sir Isaac Newton. - his most famous book was Phinciples of Mathematics which explains the laws of motion.
400
When forces on an object are unbalanced, what happens?
The object changes it motion. Whichever force is stronger will determine the direction it goes.
400
How can an object be motionless and in equilibrium?
it started motionless, then two equal forces starting acting on it which cancels them out.
500
Do machines reduce the amount of work that needs to be done?
No, they just make it easier.
500
What is a simple machine made up of a circular object and a shaft. You turn something over the shaft and it makes work easier. Give some examples.
What is a Wheel and axel. Lifting a bucket from a well and the steering wheel of a car.
500
What type of simple machine uses a stiff bar that rotates around a fixed point called a fulcrum. Give some examples.
What is a Lever. Using a see-saw to lift a box.
500
What causes you to lean against the inside of a car when the car is turning?
Your body's inertia. The car changes direction, but your body tends to keep moving straight. The same concept applies to your body in a roller coaster as it goes up and over a steep hill - your body tends to keep going up but the coaster is going down.
500
What type of simple machine uses a flat surface ramp to move something upwards? Give examples.
What is an Inclined Plane. Pushing a box up an inclined plane is easier than lifting the box.