x(20С}M(mn)40)
xжĻȻĸС}ABCDĂ(g)xxѴ(15С}ÿС}2M(mn)30)
A
Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that arent very smooth rub together to make heat energy. The faster you rub two things together, the more friction (and heat) you can make. Lets discover friction!
WHAT YOULL NEED:
Soap Water Your hands!
WHAT TO DO:
1. Make sure your hands are dry.
2. Rub your hands together until you feel the heat of your hands.
3. Now, use soap and water to get your hands very slippery ().
4. Try to make friction happen while your hands are slippery.
5. Please write down what has happened.
LETS TALK!
Friction is an energy that happens when two things rub together. When friction happens, it makes heat! When your hands are slippery, they wont make very much friction and your hands wont get so hot.
DID YOU KNOW?
1. Friction happens when you stop your fast running bike.
2. Ancient people made fires by rubbing two pieces of wood together. Friction happened though they didnt know it.
?
Friction is everywhere. Have you ever noticed situations where friction is happening? If not, ask your parents to take you out in a car. If it is not too hot, touch the tires (݆̥) of the car before and after a short drive to see how much warmer they get from friction.
x_
51. Youd better make your hands to get heat when you rub them.
A. slippery B. dry C. wet D. smooth
52. What does the word friction in this text mean in Chinese?
A. Ħ B. s C. Û D. (dng)
53. is NOT an example of friction.
A. Bike riding B. Car driving C. Hands rubbing D. Friction discovering
54. Whats the last column (Ŀ)?
A. THINK IT OVER! B. WHAT HAPPENED?
C. EVERYDAY ACTION: D. WORK WITH PARENTS!
55. This text is most probably .
A. a science report B. a car advertisement
C. a rubbing introduction D. a chemistry programme
2011пӢZ(y)ԇ}ԇ
һ(y) [1] [2] [3] [4] [5] [6] [7] [8] һ(y)
2016пϢ׃,www.artinstocktrader.com 91пW(wng)ṩпɿ(j)ԃ(xn)ȡ֔(xin)ϢHwP(gun)ԇT(mn)Ϣ