Definitions
"Energy" can be defined as...
...the ability to do work.
Kinetic energy is the energy of objects _________
in motion.
When one object does work on another, what happens to energy?
The energy is transferred.
Electrical energy is the energy of….
moving electrons
What is the equation for kinetic energy?
KE = 1/2mv^2
When does work occur?
when a force causes an object to move in the direction of the force.
Gravitational potential energy depends on…
weight and height.
Sound energy is caused by…..
an object's vibrations
A high-speed collision causes more damage than a low-speed collision because……
kinetic energy depends on the square of speed
In the kinetic energy equation, why does speed have a greater effect on kinetic energy than mass?
Speed is squared.
Potential energy is the energy of...
position.
Which energy transformation best describes a toaster while it is operating?
A. Nuclear → Radiant
B. Electrical → Thermal
C. Thermal → Nuclear
D. Electrical → Radiant
B. Electrical → Thermal
Light energy is produced by….
the vibrations of electrically charged particles
When you hit a nail with a hammer, the nail head gets warm. This is because…..
kinetic energy is converted to thermal energy via friction.
A student is playing with a 2kg tech deck and moving it down their desk at 4m/s. How much energy is the tech deck creating?
1/2(2)(4^2) = 16 J
Energy and work are expressed in the same units, which are….
Joules
Thermal energy is the total energy of…
the particles that make up an object
Nuclear energy is produced when….
two or more nuclei join together or a nucleus splits apart
In the sun, nuclear energy is produced when….
hydrogen nuclei join together to make helium
A 10kg bike is going uphill at 5m/s. How much kinetic energy is it creating?
1/2(10)(5^2) = 125 J
Mechanical energy is defined as...
...the total energy of motion and position of an object
When potential energy increases, kinetic energy must….
decrease
At the highest point of a roller coaster hill, the coaster generally has its greatest…
gravitational potential energy.
A moving skateboard slows down because of friction. Some of its kinetic energy is transformed into…
thermal energy and/or friction.
A 5kg toy car is driving down a track at 3m/s. How much kinetic energy is the car creating?
1/2(5)(3^2) = 22.5 J