1. Video
From Mechanics
(Difference between revisions)
| Line 22: | Line 22: | ||
|valign="top"| | |valign="top"| | ||
|- | |- | ||
| - | | [[Image:fig | + | | [[Image:fig drum2.jpg]] |
|valign="top"| Exploring the effects of gravity on objects can help create a definition of a force. | |valign="top"| Exploring the effects of gravity on objects can help create a definition of a force. | ||
|- | |- | ||
Revision as of 15:38, 9 April 2011
| Introduction | Video |
| The Bike Question | |
| If you are unable to do the bike experiment for yourself, try watching in on the link below. |
| The Drum Question | |
| Exploring the effects of gravity on objects can help create a definition of a force. |
| Gravity can change the motion of a ball in a number of ways. |
| A force is something that causes a change to the motion of a body. |
| Newton’s first two laws are based on an understanding of this idea of how a force changes motion. |
| In the first car the resultant force is in the direction of motion and the car gains speed.
In the second case the resultant force is zero and the car travels at a constant speed. In the third case the resultant force is backwards and the car slows down. |
| In the first case the resultant force is upwards. As the parachutist is also moving downwards, he slows down.
In the second case the resultant force is zero and the parachutist moves with a constant speed. |
| The resultant force is always downwards.
If the resultant force were zero at the highest point, the ball would stay there!! |
| No, the motion is changing from downwards to upwards.
The resultant force is upwards, for almost all of the time that the ball is in contact with the table. |
| The direction of the motion is always changing, so the forces are not in equilibrium. |
| |
| 
|
| 
|
| 
|
