| Question | answer |
| a push or a pull that causes an object to move, stop or chagne direction | force |
| equation for work | force times distance |
| force that pulls all objects toward each other | gravitation |
| forces goni in the oppoite direction and one force is greater than the other | unbalanced force |
| forces equal in size and opposite in direction | balanced force |
| force that goes against motion when two surfaces rub together | friction |
| force of pushing or pulling between magnetic poles | magnetism |
| equation for power | work divided by time |
| units for power | watts |
| units for work | joules |
| units for distance | meters |
| units for weight or force | newtons |
| What are the three main forces we studied? | gravitation, friction, magnetism |
| If a person pushes a car with 50 newtons of force, but the car doesn't move anywhere...how much work is done? | None...the car has to move in order for work to be done |
| What is the difference between gravity and gravitation | Gravitation pulls all objects towards each other. Gravity is a special type of gravitation that pulls things towards the earth. |
| What will happen if two north ends of a magnet are put together? | They will repel |
| What will happen if two south ends of a magnet are put together? | they will repel |
| What will happen if a north and south ends of a magnet are put together? | they will attract |
| Forces always act in ________. | pairs |
| Is the gravitational force bigger or smaller when objects are farther apart | small gravitational force |
| If an object is extremely large, like the sun, it the gravitational force bigger or smaller? | bigger gravitational force |
| T/F? Gravity pulls people to the earth and earth towards the people | True |
| If a moving object stops, then the forces must be ___________ | unbalanced |
| If a moving object keeps moving at the same speed and same direction, the forces must be | balanced |
| If a stopped object starts moving, the forces must be | unbalanced |
| If an object isn't moving, the forces must be | balanced |
| What is the net force of a tug of war game if one side pulls with 50 newton and the other side pulls with 20 newton? | 30 newtons |
| How much work is down in your lift a 10 newton chair 4 meters off the floor? | 10 newtons x 4 meters = 40 joules |
| How must power does John exert if it took 100 joules of work to move that box in 20 second? | 100 joules / 20 second = 5 watts |
