| 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 |