Energy Forms and ch-ch-ch-ch-Changes
Chemical potential in the gasoline, and gravitational potential in the plane's distance from Earth.
What are the two kinds of relationships that kinetic energy and mass have?
Proportional and linear
What is gravitational potential energy? What does it depend on?
Gravitational potential energy is the potential energy stored in a system of objects interacting due to gravitational forces. It depends on the mass of the objects in the system and the distance between the objects in a system.
What is the law of conservation of energy?
Energy can never be created or destroyed, only transferred or transformed. OR As potential energy increases, kinetic energy increases and vice versa. Energy is always conserved.
Energy exists in which two forms? What is the difference?
Energy exists as kinetic energy and potential energy. Kinetic energy is the energy an object has due to its motion. Potential energy is the stored energy in a system due to the placement of objects in the system.
If you dropped a 4.5 kg (10 lb) bowling ball and a 5.4 kg (12 lb) bowling ball from the same height, which would you expect to have more kinetic energy? Why?
The 5.4 kg (12 lb) bowling ball would have more kinetic energy because it has more mass.
What does the magnetic potential energy stored in a system depend on?
(3 things)
strength of magnets, orientation of magnets, distance between magnets
Why is it that when you drop a ball, it doesn't return to it's original height?
Some energy is always transferred out of the system as thermal energy and sometimes as sound energy.
A snowboarder glides from the top of a mountain to the bottom. At what point does the snowboarder have the most potential energy? The most kinetic energy?
The snowboarder has the most potential energy when they are high on the mountain. They have the most kinetic energy at their fastest speed going down the mountain.
What does it mean for two variables to have a linear relationship?
When the two variables can be represented by a straight line on a graph.
When you pull two magnets apart in which the north pole of one is next to the south pole of the other, do you think the magnetic potential energy of the system increases or decreases?
It increases.
Why did the bowling ball not hit Bill Nye in the face?
Kinetic energy can never be more than potential energy, because the system only has the amount of energy that Bill Nye put into it to begin with.
Imagine you perform an experiment measuring the top speed of bicycles of different masses. All other factors are the same. What forms of energy are scientists measuring in this experiment?
Kinetic energy only.
What does it mean for two variables to have a proportional relationship?
The ratio between them is always the same. They have a constant rate of change.
What will happen as the north poles of two magnets magnets are pushed closer together?
The magnetic potential energy will increase.
Give an example of a system that appears to "lose" energy.
Answers will vary, could include friction causing something to slow down or sound or heat being produced.
A snowboarder glides from the top of a mountain to the bottom. Explain the transformation of energy in the system of the snowboarder and the mountain.
At the top of the mountain the snowboarder has a lot of potential energy. As the snowboarder begins to move down the mountain, potential energy is transformed into kinetic energy. As the snowboarder approaches the bottom of the hill, there is less potential and more kinetic energy.
Explain the relationship between kinetic energy and speed
Generally, the kinetic energy of an object increases as its speed increases. The relationship between kinetic energy and speed is a nonlinear relationship. Kinetic energy is proportional to speed squared.
How could two objects change in order for there to be a stronger electric force between them?
They could have a greater amount of charge added to them, or change the distance between them.
"When the kinetic energy of an object changes, there must be some other change in energy at the same time."
Make an argument for whether or not this statement is true. Use the law of conservation of energy and evidence from what you've learned in the unit.
Energy is always conserved. So the kinetic energy cannot arise out of thin air or disappear - it must come from somewhere or go somewhere to obey the law of conservation of energy. Examples will vary. In all cases, energy is never gained or lost - it is conserved