Gravity
On Earth, what does gravity make things do?
Who thought the weight of an object determined how fast it falls through the air?
Aristotle
Who is known for the three laws of motion?
*FULL NAME*
Sir Isaac Newton
What is the energy of motion called?
Kinetic energy
What is the term for all the forces acting on an object?
Net force
What force of attraction exists between masses?
Gravitational force
Who is known as the father of modern science?
Galileo Galilei
How many basic principles are in Newton's laws of motion?
Three
What is energy stored in the position of an object called?
Potential energy
What is the net vertical force on a passenger standing in a stopped elevator?
0 N
What is the acceleration of gravity measured to be on Earth?
9.8 m/s2
Why did Galileo use balls rolling down ramps to study gravity?
The motion was slower so he could observe it
According to Newton's First Law, what happens to an object at rest unless an outside force acts on it?
It stays at rest
As a marble rolls down a ramp and speeds up, what happens to its kinetic energy?
It increases
How does a person feel when an elevator accelerates downward?
Lighter
What happens to falling objects because of Earth's gravity?
They are pulled toward Earth's surface
What happened when Galileo used steeper ramps?
The balls had greater acceleration
According to Newton's Second Law, acceleration is directly proportional to what?
Force
As a marble rolls lower on the ramp, what happens to its potential energy?
It decreases
What force causes a cube to eventually stop moving across the table?
Friction
Accelerates
What did Galileo show about objects of different sizes and masses?
They fall together and hit the ground at the same time
All objects fall with the same rate of acceleration (excluding air resistance)
What does Newton's Third Law say happens for every action or force?
There is an equal and opposite reaction or force
When you place a marble higher on the ramp, what happens to its potential energy?
It increases
When friction acts on the cube and table, what type of energy does the kinetic energy transfer to?
Thermal energy