Kinetic Energy
Kinetic Energy is the energy of ____________.
Movement
stored
As objects heat up, their molecules move ___________.
More quickly.
What two variables affect gravity?
Distance and mass
What natural satellite orbits the Earth?
The Moon
On a rollercoaster, is the kinetic energy greatest at the top of the hill or the bottom? Explain why.
Kinetic energy is greatest at the bottom, because the rollercoaster has gained speed by moving downhill. This happens because of gravity.
Explain how a slingshot is an example of potential energy
When you touch something hot, the hot object _________ its heat to you.
transfers
Define mass
The amount of matter ("stuff") in an object
What two variables affect an object's orbit?
Gravity and velocity ("speed")
What two variables affect kinetic energy?
Mass and speed
You're climbing a ladder. Do you have more potential energy at the bottom of the ladder, middle of the ladder, or top of the ladder? Explain why.
You have the most potential energy at the top of the ladder. Because you are higher up, you have stored more energy and will have more kinetic energy when you fall.
There are three types of thermal energy transfer. What are they?
Conduction, convection, radiation
Explain why gravity is less on the Moon than on the Earth.
The Moon has less mass than the Earth, and therefore less gravity.
What is the difference between a circular orbit and an elliptical orbit?
A football player kicks a field goal. Is this an example of energy transfer or transformation? Explain.
This is energy transfer. The kinetic energy of the football player's foot transfers to the football, which makes it move.
You climb to the top of high diving board, then cannonball off. Is this an example of energy transfer or transformation? Explain why.
This is energy transformation. Climbing up to the high diving board increases your potential energy. When you jump off, that potential energy converts into kinetic energy.
Explain why thermal energy is a form of kinetic energy.
Thermal energy is the total kinetic energy of an object (how quickly its molecules are moving around).
The formula for gravity is F = G (m1 * m2/R^2). What does G stand for?
The universal gravitational constant
Why doesn't the Earth orbit around the Moon?
The Earth has more mass than the Moon.
Explain how kinetic energy is related to state of matter changes.
When molecules move faster, they have more kinetic energy. Moving faster is what causes them to change their state of matter, from a solid to a liquid to a gas.
There are two main types of potential energy. Gravitational potential energy is one. What is the other? (Hint: we learned about it in a video)
Elastic potential energy
You have 0.5 cups of water in glass one and 2.5 cups of water in glass two. Both are 82 degrees. Explain why their thermal energy is different.
The 2.5 cups of water in glass two has more total molecules, and therefore more movement/kinetic energy.
People used to believe that the Earth is at the center of the solar system. Use what you know about gravity to explain why that can't be true.
The Sun has much more mass than the Earth, and therefore more gravity. This means that the Earth orbits around the Sun, not the other way around.
Explain how gravity causes the Earth to orbit the Sun.
Gravity pulls us towards the Sun. Our velocity moves us away. The balance between them causes an orbit.