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 aren't very smooth rub together to make heat energy.The faster you rub two things together，the more friction (and heat) you can make. Let's discover friction!

WHAT YOU'LL NEED：

●A piece of 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 a piece of soap and water to get your hands very slippery (滑的)．

4.Try to make friction happen while your hands are slippery.

5.Please write down what has happened.

LET'S TALK!

Friction is a kind of energy that happens when two things rub together. When friction happens, it makes heat! When your hands are slippery, they won't make much friction and your hands won't 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 didn't 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 (輪胎) of the car before and after a short drive to see how much warmer they get from friction.

1.You'd better make your hands ________ to get heat when you rub them.

A. slippery B. dry C. wet D. smooth

2.What does the underlined word “friction” in this text mean in Chinese?

A. 摩擦 B. 冷卻 C. 膨脹 D. 震動(dòng)

3.________ is NOT an example of friction.

A. Bike riding B. Car driving

C. Hands rubbing D. Friction discovering

4.What's the last column (欄目)?

A. THINK IT OVER!

B. WHAT HAPPENED?

C. EVERYDAY ACTION：

D. WORK WITH PARENTS!

5.This text is most probably ________.

A. a science report B. a car advertisement

C. a rubbing introduction D. a chemistry programme

1.B 2.A 3.D 4.C 5.A 【解析】 1. 2. 3. 4. 5.
練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目：初中英語(yǔ) 來(lái)源：人教版九年級(jí)下冊(cè)英語(yǔ) unit11 第5課時(shí) 測(cè)試 題型：單選題

The bad boss made the children _______ long and _______ heavy work.

A. to work; to do B. working; doing C. work; do D. worked; did

C 【解析】 句意：這個(gè)壞老板讓孩子們工作了很長(zhǎng)時(shí)間并且做了很多沉重的工作。“make sb do…”就是“使某人做…”，本題是“使孩子們工作”和“使孩子們做工作”，故選C。

查看答案和解析>>

科目：初中英語(yǔ) 來(lái)源：2018年廣東中考英語(yǔ)沖刺卷 題型：單選題

If you fail in the exam， you ________ him down．

A. would let B. lets C. will let D. let

C 【解析】句意：如果你考試不及格，你就會(huì)讓他失望的。would let是過(guò)去將來(lái)時(shí)；lets一般現(xiàn)在時(shí)；will let一般將來(lái)時(shí)；let讓?zhuān)瑒?dòng)詞原形。let sb. down讓某人失望，是一個(gè)固定短語(yǔ)。句中If引導(dǎo)的是條件狀語(yǔ)從句，從句中用一般現(xiàn)在時(shí)態(tài)，主句應(yīng)用一般將來(lái)時(shí)態(tài)，故選C。

查看答案和解析>>

科目：初中英語(yǔ) 來(lái)源：2018年廣東中考英語(yǔ)沖刺卷 題型：單選題

—__________ are you going to buy for your father for Father’s Day?

—A T?shirt.

A. What B. When C. Where D. How

A 【解析】句意：-父親節(jié)的時(shí)候你打算給你的父親買(mǎi)什么？-一件T恤衫。What什么；When什么時(shí)候；Where 在哪里；How怎樣。根據(jù)下面的回答A T shirt可知，這里問(wèn)的是買(mǎi)什么東西，故疑問(wèn)詞用what，選A。

查看答案和解析>>

科目：初中英語(yǔ) 來(lái)源：2018年廣東中考英語(yǔ)沖刺卷 題型：其他題

The library is on the left _________ of the bank.

A. said B. send C. sad D. side

D 【解析】試題句意：圖書(shū)館在銀行的左邊。said音標(biāo)為：[sed]；send音標(biāo)為：[send]；sad音標(biāo)為[s?d]；side音標(biāo)為：[sa?d]。故選D。

查看答案和解析>>

科目：初中英語(yǔ) 來(lái)源：2018年秋冀教版九年級(jí)英語(yǔ)Unit 5過(guò)關(guān)測(cè)試卷 題型：單選題

We'll go to the park ________ there is a heavy rain tomorrow.

A. unless B. since C. as soon as D. if

A 【解析】句意：如果明天沒(méi)有大雨，我們將去公園。A. unless除非，如果不； B. since自從，既然； C. as soon as一……就； D. if如果。根據(jù)We'll go to the park我們?nèi)ス珗@；所以空格后應(yīng)該是不下雨。故選A。

查看答案和解析>>

科目：初中英語(yǔ) 來(lái)源：2018年秋冀教版九年級(jí)英語(yǔ)Unit 5過(guò)關(guān)測(cè)試卷 題型：單選題

Let's get some ________ about tourism on the Internet.

A. information B. message

C. invention D. experiments

A 【解析】句意：讓我們?cè)诰W(wǎng)上取得一些關(guān)于旅游業(yè)的信息吧。A. information信息，是不可數(shù)名詞； B. message消息，是可數(shù)名詞；當(dāng)前面有some時(shí)，該詞應(yīng)該用復(fù)數(shù)形式，故排除B；C. invention邀請(qǐng)；可數(shù)名詞，當(dāng)前面有some時(shí)，該詞應(yīng)該用復(fù)數(shù)形式，故排除C； D. experiments實(shí)驗(yàn)。根據(jù)on the Internet可知，在網(wǎng)上得到了應(yīng)該是信息。故選A。...

查看答案和解析>>

科目：初中英語(yǔ) 來(lái)源：2018年山東省中考英語(yǔ)題型專(zhuān)項(xiàng)練習(xí)：任務(wù)型閱讀 題型：回答問(wèn)題

If you think it is cold where you are at the moment, then a visit to the Russian village of Oymyakon might just change your mind. The small village is in the heart of Siberia(西伯利亞). The name Oymyakon means “non-freezing water” because of a nearby hot spring, but it is indeed the coldest inhabited(有人居住的) place on the earth.

Oymyakon sits just a few hundred miles from the Arctic Circle(北極圈). The average(平均) temperature remains below 50°C in winter and the lowest temperature there was 67.7°C. This is the lowest recorded temperature in the Northern Hemisphere(北半球). Oymyakon is white in winter, since everything is frozen and covered with thick snow. But it’s also dark—the length of daytime is only three hours.

Because of the weather, people’s life there is inconvenient(不方便的), yet simple and traditional. Most homes still burn coal and wood for heat. When people go outside, they have to wear fur coats to stay warm. They can’t wear glasses, or the glasses will freeze to their face. There are few modern conveniences for them to enjoy. People don’t use mobile phones, because the batteries(電池) cannot work in such low temperatures. Cars can only be placed in heated garages. The ones left outside must keep running, or they won’t restart.

1.Which country does the village Oymyakon lie in?

____________________________________________

2.How far is it from Oymyakon to the Arctic Circle?

____________________________________________

3.Which season has the shortest daytime in the village Oymyakon?

____________________________________________

4.What do the villagers wear when they go outdoors?

____________________________________________

5.Why can’t the mobile phones be used in Oymyakon?

____________________________________________

1.Russia 2.A few hundred miles. 3.Winter. 4.Fur coats 5.Because the batteries cannot work in such low temperatures. 【解析】【主旨大意】本文是一篇說(shuō)明文，主要介紹了俄羅斯的一個(gè)叫做Oymyakon的小村莊的氣候以及那兒的人們的生活方式。 1.題意：...

查看答案和解析>>

科目：初中英語(yǔ) 來(lái)源：廣東省東莞市2018屆九年級(jí)下學(xué)期第二次模擬考試（含聽(tīng)力）英語(yǔ)試卷 題型：聽(tīng)句子或?qū)υ掃x擇圖片

（題文）What’s the speaker’s favorite sport?

A. B. C.

C 【解析】略

查看答案和解析>>

同步練習(xí)冊(cè)答案