## Wednesday, February 22, 2017

### speed lab ball bearing

The Effect of Gravity on Speed
Introduction
Gravity provides a constant acceleration (force) on an object.  The effect is changed by using ramps at different angles. In this lab, you will find the optimal angle to maximize acceleration on a ball bearing so it travels the farthest and/or the fastest.  Friction is the opposing force created by the surface interactions.  Whenever something rolls due to a force, friction will oppose this force and slow it down.

Equipment needed:
Timer                                       Ramp                           Ball Bearing
Graph Paper (2)                       Ruler

Procedure:
1.         Put the ramp against the seat of a chair.  Place the ramp and chair so that the ramp points towards the hallway.  Have your teammate on the other end of the hallway.
2.         Place the ball bearing at the top of the ramp.
3.         Lift the ramp 20 cm and release the ball bearing
4.         Time how long it takes to travel  5 meters.
5.         See how far it will go..
6.         Repeat the experiment three times for each height then do 40 cm, 60 cm, and 80 cm.

 Height Time to travel 5 meters Distance travelled 20 2.98 s 5 m 40 3.66 s 5 m 60 8 s 5 m 80 6 s 44 cm

Observations: When the height is high, the time is short, the height is low the time is long

Analysis
1.         Describe how the ball rolls off the ramp at each height—discuss the effect of bouncing or other factors.

: When the height is high the ball will bounce and the distance also shorter than the ball that doesn't bounce.

2.         Discuss what is the fastest speed reached and any factors that could improve this.
:  2.98 s

3.         Does the ball travel in a straight line, why or why not?
:  No, because it is circle so it can go anyaway.

## Essay

This year is 2016, I have done a lot of things. This year I              have start studied in Panyarat high school. I have a lot of                 good friends. They are always help each other. In next year I           plan to more diligent in learning and speak less in bad words.

## Wednesday, February 1, 2017

### Cloud

Cloud

Stratus: The gray cloud that covers skylight rain and drizzle.

Cirrus: Feathery cloud, good weather but rain or snow may be on the way.

Cumulus: Fluffy white clouds fair (good) weather