Energy
What is Energy?
The ability to do work
What is work?
The use of force to move an object a certain distance
A rod that rotates on a fixed point.
Lever
What is kinetic energy?
Energy of motion or moving energy
What is potential energy?
Energy of position or stored energy
What is the Law of Conservation of Energy
Energy cannot be created or destroyed.
What is the equation for work and the units for each variable?
Work (J) = Force (N) x distance (m)
The ______________ or ___________ force is how much force is being applied to a simple machine.
effort, input
If mass of an object remains constant and its velocity is doubled then the kinetic energy of the object is___________. HINT use the equation for KE
Quadrupled (increased by 4)
If the mass of an object remains constant and its height is doubled, then its gravitational potential energy is_____________
Doubled
Why is it impossible to transfer 100% of the energy used when doing work?
Some energy is always lost to friction
What is transferred when work is done?
Energy
Name the 6 simple machines
lever, pulley, wheel and axle, inclined plane, wedge, screw
When an object reaches its highest velocity it has ________________ kinetic energy.
Maximum
Mass and height are _________ proportional to gravitational potential energy.
Directly
How does the Law of Conservation account for "lost energy"? **hint: what is "lost energy" transformed into**
"Lost energy" becomes thermal energy or another form such as sound
William used 60 N to run a 50 m dash. How much work did he do?
60 N x 50 m = 3,000J
A machine always loses some energy in the form of __________ energy.
Thermal
Kinetic energy decreases as __________ and __________ decrease.
Mass and velocity
Gravitational potential energy increases as __________ and __________ increase.
mass and height
Explain the relationship between kinetic energy and potential energy.
Kinetic energy and potential energy are both inversely related. For example, if kinetic energy increases, potential energy decreases.
How are work and force related?
Work and force are directly related. For example, when force increases, work also increases.
3 ways simple machines make work easier. HINT: use the word force is every answer
Simple machines make work easier by
1.changing the size of force
2. direction of force
3. distance the force is applied.
3 forms of kinetic energy
Thermal energy Electrical energy, Sound Energy, Radiant Energy visible light, x-rays, gamma rays radio waves, solar), Energy of Motion
3 forms of potential energy
1. Chemical Energy, Gravitational energy, Nuclear Energy, Stored Mechanical Energy (Ex. compressed springs and stretched rubber bands)