Wednesday, February 22, 2017

writing assessment

In this year, I did so many things in Kru Gary class. Kru Gary taught me about science in this year. He is my favourite science teacher. Next year, I will study harder for science to be a medical doctor in the future like my dad. This year Kru Gary's class always fun. I love this class. I want Kru Gary to teach me in next year. He made me like this subject. His fantastic word is "No pressure". He always says that in every class.

Thursday, February 2, 2017

cloud lab

This is cirrus cloud

This is Cumulus cloud

The last one is Stratus cloud

Ball Bearing lab

The Effect of Gravity on Speed

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

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.

Time to travel 5 meters
Distance traveled
4.72 s
5.9 m
3.69 s
6 m
4.91 s
5.6 m
8.78 s
5.6 m
6.69 s
6.2 m 
6.82 s
10 m 







The ball released from higher ramp travel faster and further. The ball release at height 80 cm went faster than and further than 20 cm.

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

Answer : The ball roll off at higher position went faster and longer distance than lower height. The result of the height of the ramp cause more acceleration of the ball

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

Answer : The ball with fastest speed was the one at highest angle. To improve speed, we need to change the angle higher.

3. Does the ball travel in a straight line, why or why not ?

Answer : Yes, because of the surface was smooth and does not cause friction between ball and ramp