| A | B |
|---|
| When is work done on an object? | when the object moves in the direction of a force acting on it |
| When is work not done? | when the object does not move |
| Work is equal to what? | force X distance |
| What is a machine? | a device that helps do work |
| What do machines change? | the size or direction of the force used to do work |
| What does the mechanical advantage of a machine equal? | the resistance force divided by the effort force |
| What is the mechanical efficiency of a machine? | a comparison of work output to work input |
| What prevents a machine being 100% efficient? | friction |
| What are kinds of simple machines? | inclined planes, wedges, screws, levers, wheels & axles, pulleys |
| What is a compound machine? | a combination of two or more simple machines working together as a system |
| What causes mechanical energy? | is due to the position of something(potential energy) or the movement of something(kinetic energy) |
| What are the forms of energy? | mechanical, nuclear, heat, chemical, and electromagnetic |
| What can energy do? | change from one form to another |
| What is the Law of Conservation of Mass and Energy? | the total amount of mass and energy in the universe is constant(energy and mass cannot be created or destroyed) |
