## Wednesday, February 21, 2018

### Buoyancy lab

 Object Weight in Air Apparent weight in water Buoyant force Pulley weight in air Length in String 1 10N 7N 3N 10N 44cm 2 4.2N 3.2N 1N 4N 40.5cm 3 2N 1.75N 0.25N 1.2N 40cm 4 1.9N 1.6N 0.3N 1N 37.5cm 5 0.9N 0.75N 0.15N 0.75N 37cm 6 0.4N 0.3N 0.1N 0.75N 32.5cm 7 0.15N 0.1N 0.05N 0.5N 31cm 8 0.1N 0.05N 0.05N 0.25N 28cm 9 0.05N 0.005N 0.045N 0.2N 24cm

## Wednesday, February 14, 2018

### ฺฺBalloon and water stream lab

1. Infer Why did you rub the balloon on your sweater? Predict what might have happened if you simply touched the balloon to your sweater instead of rubbing it.

Answer The sweater holds electrons more loosely than the balloon. When they comes in contact, electrons from the sweater transfer the balloon. The balloon gained electrons and the sweater lost electrons. Therefore rubbing the balloon creates a static charge on both objects. If we simply touched the balloon to the sweater, there won't be any electrons transferred between objects. Because electrons in the both objects are already equal.

2. Key Concept Why do you think the balloon interacted the way it did with your sweater and with the stream of water?

Answer The stream of water is made out of positive and negative charges. But as the balloon has negative charge, the positive charged parts of the water molecules are attracted to the negative charge and move the water stream toward the balloon.

## Wednesday, January 10, 2018

### Vector mapping

Start point -- canteen

1. East 93 degree - 49 steps
2. South 189 degree - 23 steps
3. East 93 degree - 2 steps
4. East 93 degree - 11 steps up the stairs
5. North 6 degree - 3 steps
6. West 279 degree - 7 steps up the stairs
7. West 279 degree - 6 steps
8. South 189 degree - 30 steps
9. North 6 degree - 10 steps
10. South 189 degree - 4 steps
End point -- M1/101

## Color and light lab

Materials :
• flashlight
• red filter
• blue filter
• yellow filter
• green filter
• purple filter
• white paper
• monitor (mobile phone)
1.  r+g, r+b, b+g
2. work with another group—put a color paddle over the flashlight, shine on white paper—so a red, a green, and a blue
Activity B: color subtraction
1. view white paper through color paddles—record results
2. view colored objects through color paddles
Data :

 white light = blue + green + red
 red light

 Filter color Seeing through filter(s) Shine light on every filter(s) on white paper (subtraction) Put each filter to each flashlight and shine it on white paper (addition) red red red red blue light blue light blue light blue green light green light green light green yellow yellow yellow yellow purple Purple (with a little bit of pink) Purple (with a little bit of pink) Purple (with a little bit of pink) red+green Brown (with some yellow) Brown (with some yellow) Yellow (have some orange) red+blue Purple purple Magenta (purple with pink) blue+green Turquoise (blue with some green) Turquoise (blue with some green) Turquoise (blue with some green) blue+green +red black Black (with some brown) white

 green light

 blue light

## Materials

• milk
• bag
• test tube rack
• bucket
• salt

## Procedure

First step: We pour the milk into the bag and close it.
Second step:  We put ice then add salt to cover the bag.
Third step: We use test tube rack to cause movement to the ice which will make the milk freeze.
Fourth step: After the milk starting to freeze, we add toppings to the milk and did the same as step 3 until the milk completely freeze.
Fifth step: We washes our hand and make sure the salt doesn't come into the bag while we are opening.
Sixth step: Enjoy the ice cream

## Results

This lab shows us that liquid milk turns into solid by making it cools down. The salt makes the process faster by making the temperature low, so it takes less time than using only ice.

## Questions

1)  why do we add salt to the ice?
It makes the bonds of water change and decreases the freezing point. Therefore, the ice doesn't melt and can cause the milk to freeze.

2)   why do we add the cookies and other things, only after the milk has frozen slightly
Because toppings are a heat capacity which can slow the process down.

3)  what are two factors that affect the freezing you think?
Movement and temperature

4)  why do you need a bit of air in the bag?
A bit of air in the bag allow milk to move and contact with ice.

## Wednesday, June 7, 2017

### Rock lab

Results

Calculate the density of each of your mineral samples. How could you use the densities to identify the minerals?
- When the density of minerals is the same they are the same type of mineral.
Would density or color be more useful in identifying a particular mineral? Explain your answer.
- Density and color are both useful. Because both of them can use to identify differents types of minerals.