Unit 4 Astronomy: the science of the stars Teaching goals教学目标 1 Target language目标语言 a重点词汇和短语 preparation, instruction, unexpected, a set of, pay attention to as well as b交际用语 Practice giving instructions Please look at/listen to Please check that Please pay attention t Dont forget to. Youd better Make sure you You mustn’t 2Abi| ity goals能力目标 a Enable the Ss to make a list of things that they need b Enable the ss to talk about giving instructions C. Enable the Ss to play different roles in a conversation 3 Learning ability goals学能目标 b help the ss learn how to talk about giving instructions C Enable the Ss learn how to play different roles in a conversation. Teaching important and difficult points教学重点难点 a. Teach the Ss how to how to talk about giving instructions b help the ss to learn how to play different roles in a conversation. Teaching methods教学方法 a. Pairs wol group b. Discussion and co Teaching aids教具准备 2 A projector
Unit 4 Astronomy: the science of the stars Teaching goals 教学目标 1 Target language 目标语言 a 重点词汇和短语 preparation, instruction, unexpected, a set of, pay attention to, as well as b 交际用语 Practice giving instructions Please look at/ listen to… Please check that… You need… Please pay attention to… Don’t forget to… You’d better… Make sure you… Watch out for… You mustn’t… 2 Ability goals 能力目标 a. Enable the Ss to make a list of things that they need. b. Enable the Ss to talk about giving instructions. c.. Enable the Ss to play different roles in a conversation. 3 Learning ability goals 学能目标 a. Learn how to make a list of things that they need b Help the Ss learn how to talk about giving instructions c. Enable the Ss learn how to play different roles in a conversation. Teaching important and difficult points 教学重点难点 a. Teach the Ss how to how to talk about giving instructions b. Help the Ss to learn how to play different roles in a conversation. Teaching methods 教学方法 a. Pairs work and group work b. Discussion and cooperative learning Teaching aids 教具准备 1 A computer 2 A projector
Teaching procedures&ways教学过程与方式 step I Revision Ask some of the Ss to read his/ her passage about gravity. One possible passage Sir Isaac Newton the universal law of gravitation There is a popular story that Newton was sitting under an apple tree, an apple fell on his head, and he suddenly thought of the Universal Law of gravitation. As in all such legends this is almost certainly not true in its details, but the story contains elements of what actually happened What Really Happened with the Apple? Probably the more correct version of the story is that Newton upon observing an apple fall from a tree began to think along the following lines: The apple is accelerated, since its velocity changes from zero as it is hanging on the tree and moves toward the ground thus, by Newton s 2nd law there must be a force that acts on the apple to cause this acceleration Let 's call this force"gravity, and the associated acceleration the"accleration due to gravity". then imagine the apple tree is twice as high again, we expect the apple to be accelerated toward the ground so this suggests that this force that we call gravity reaches to the top of the tallest apple tree Sir Isaacs Most Excellent idea Nov Newton 's truly brilliant insight: if the force of gravity reaches to the top of the highest tree it not reach even further; in particular might it not reach all the way to the orbit of the Moon! Then, the orbit of the moon about the earth could be a consequence of the gravitational force, because the acceleration due to gravity could change the velocity of the moon in just such a way that it followed an orbit around the earth
Teaching procedures & ways 教学过程与方式 Step I Revision Ask some of the Ss to read his / her passage about gravity. One possible passage: Sir Isaac Newton: The Universal Law of Gravitation There is a popular story that Newton was sitting under an apple tree, an apple fell on his head, and he suddenly thought of the Universal Law of Gravitation. As in all such legends, this is almost certainly not true in its details, but the story contains elements of what actually happened. What Really Happened with the Apple? Probably the more correct version of the story is that Newton, upon observing an apple fall from a tree, began to think along the following lines: The apple is accelerated, since its velocity changes from zero as it is hanging on the tree and moves toward the ground. Thus, by Newton's 2nd Law there must be a force that acts on the apple to cause this acceleration. Let's call this force "gravity", and the associated acceleration the "accleration due to gravity". Then imagine the apple tree is twice as high. Again, we expect the apple to be accelerated toward the ground, so this suggests that this force that we call gravity reaches to the top of the tallest apple tree. Sir Isaac's Most Excellent Idea Now came Newton's truly brilliant insight: if the force of gravity reaches to the top of the highest tree, might it not reach even further; in particular, might it not reach all the way to the orbit of the Moon! Then, the orbit of the Moon about the Earth could be a consequence of the gravitational force, because the acceleration due to gravity could change the velocity of the Moon in just such a way that it followed an orbit around the earth
This can be illustrated with the thought experiment shown in the following figure. Suppose we fire a cannon horizontally from a high mountain; the projectile will eventually fall to earth, as indicated by the shortest trajectory in the figure, because of the gravitational force directed toward the center of the Earth and the associated acceleration. ( Remember that an acceleration is a change in velocity and that velocity is a vector, so it has both a magnitude and a direction. Thus, an acceleration occurs if either or both the magnitude and the direction of the velocity change. Earth But as we increase the muzzle velocity for our imaginary cannon, the projectile will travel furthe and further before returning to earth. Finally Newton reasoned that if the cannon projected the cannon ball with exactly the right velocity the projectile would travel completely around the earth, always falling in the gravitational field but never reaching the earth, which is curving away at the same rate that the projectile falls That is, the cannon ball would have been put into orbit around the earth. Newton concluded that the orbit of the moon was of exactly the same nature: the moon continuously"fell"in its path around the earth because of the acceleration due to gravity thus producing its orbit By such reasoning, Newton came to the conclusion that any two objects in the Universe exert gravitational attraction on each other, with the force having a universal form
This can be illustrated with the thought experiment shown in the following figure. Suppose we fire a cannon horizontally from a high mountain; the projectile will eventually fall to earth, as indicated by the shortest trajectory in the figure, because of the gravitational force directed toward the center of the Earth and the associated acceleration. (Remember that an acceleration is a change in velocity and that velocity is a vector, so it has both a magnitude and a direction. Thus, an acceleration occurs if either or both the magnitude and the direction of the velocity change.) But as we increase the muzzle velocity for our imaginary cannon, the projectile will travel further and further before returning to earth. Finally, Newton reasoned that if the cannon projected the cannon ball with exactly the right velocity, the projectile would travel completely around the Earth, always falling in the gravitational field but never reaching the Earth, which is curving away at the same rate that the projectile falls. That is, the cannon ball would have been put into orbit around the Earth. Newton concluded that the orbit of the Moon was of exactly the same nature: the Moon continuously "fell" in its path around the Earth because of the acceleration due to gravity, thus producing its orbit. By such reasoning, Newton came to the conclusion that any two objects in the Universe exert gravitational attraction on each other, with the force having a universal form:
Law of universal gravitation Every object in the Universe attracts every other object with a force directed along the line of centers for the two Prop product of their masses and inversely proportional to the square of the separation between the two objects G is the universal gravitational constant The constant of proportionality G is known as the universal gravitational constant. It is termed a universal constant"because it is thought to be the same at all places and all times, and thus universally characterizes the intrinsic strength of the gravitational force Step ll Presentation T: Do you remember the conversation between Li Yanping and Professor Wallis? T: We all know that space walk is difficult and dangerous. What should an astronaut take with him? S4: gravity boots T: Great! Do you know the usage of them? Now discuss them with your partner according to the form on Page 31. You can refer to our listening material on Page 65 When Ss discuss Teacher walk around the classroom to give them some help
The constant of proportionality G is known as the universal gravitational constant. It is termed a "universal constant" because it is thought to be the same at all places and all times, and thus universally characterizes the intrinsic strength of the gravitational force. Step II Presentation T: Do you remember the conversation between Li Yanping and Professor Wallis? S1: Yes. T: We all know that space walk is difficult and dangerous. What should an astronaut take with him? S2: oxygen can. S3: spacesuit. S4: gravity boots. S5: water system. S6: special food. S7: special ropes. T: Great! Do you know the usage of them? Now discuss them with your partner according to the form on Page31. You can refer to our listening material on Page65. When Ss discuss. Teacher walk around the classroom to give them some help
Step Ill Speaking (Page31) (After a few minutes. T: Have you finished? Now speak one or two sentences for each equipment you should take Sa: I will take water with me in my spacesuit in order to warm or cool me if it's too cold or too hot. Sb: I will take oxygen can on my back in order to help me breathe oxygen in space. Sc: I'll wear spacesuit. t can protect me from many dangers. It can carry many necessary things in or on it Sd: I'lltake space buggy in order to travel on the moon Se: I'lltake a rope to tie me to the spaceship or I'll fly away. Sf: I'lltake special food so that I can eat easily, because the food will float in space Sg: /'ll wear special sunglasses in order to protect my eyes Sh: I'll take space camera in order to take photos T: Wonderful! Anything else? Si: I'll wear space boots in order to walk there. T: Very good. You,'ve done an excellent job! Do you know how to fill in the form now? Ss: Yes T: Now look at the screen and check your answer. sample answer To keep you cool Spaceship with water to cool you to help you breathe oxygen Oxygen tanks to carry on your back
Step III Speaking (Page31) (After a few minutes.) T: Have you finished? Now speak one or two sentences for each equipment you should take. Sa: I will take water with me in my spacesuit in order to warm or cool me if it’s too cold or too hot. Sb: I will take oxygen can on my back in order to help me breathe oxygen in space. Sc: I’ll wear spacesuit. t can protect me from many dangers. It can carry many necessary things in or on it. Sd: I’ll take space buggy in order to travel on the moon. Se: I’ll take a rope to tie me to the spaceship, or I’ll fly away. Sf: I’ll take special food so that I can eat easily, because the food will float in space. Sg: I’ll wear special sunglasses in order to protect my eyes. Sh: I’ll take space camera in order to take photos. T: Wonderful! Anything else? Si: I’ll wear space boots in order to walk there. T: Very good. You’ve done an excellent job! Do you know how to fill in the form now? Ss: Yes. T: Now look at the screen and check your answer. Sample answer: To keep you cool Spaceship with water to cool you to help you breathe oxygen Oxygen tanks to carry on your back
Clothes for exercise spacesuit To travel on the moon space buggy To protect your skin Spacesuit To stop you flying off into space A rope to tie you to the spaceship To stop your food from floating Space food that you can eat more easily Clothes for walking on the moon Spacesuit To give shade Sunglasses in your spacesuit helmet To take photographs Space camera Step IV Talking(Page62) The task asks the students to work in pairs and give a friend a number of"does"and"don'ts"for ing into space. they need to make suggestions using the phrases that they have been given to help them. When they have worked out the advice they can write the suggestions down and read them out to the class Show the useful expressions Please look at/ listen to Please check that Please pay attention to Dont forget to. Youd better Make sure you
Clothes for exercise spacesuit To travel on the moon Space buggy To protect your skin Spacesuit To stop you flying off into space A rope to tie you to the spaceship To stop your food from floating away Space food that you can eat more easily Clothes for walking on the moon Spacesuit To give shade Sunglasses in your spacesuit helmet To take photographs Space camera Step IV Talking (Page62) The task asks the students to work in pairs and give a friend a number of “does” and “don’ts” for going into space. They need to make suggestions using the phrases that they have been given to help them. When they have worked out the advice they can write the suggestions down and read them out to the class. Show the useful expressions Please look at/ listen to… Please check that… You need… Please pay attention to… Don’t forget to… You’d better… Make sure you…
Watch out for You mustn't T: Now discuss it in pairs. Then I will ask some pairs to read out their instructions. S1: I' m going to visit a comet. I'm leaving tomorrow. S2:How exciting!Please check that you have got the correct sort of spacesuit. You need the kind that will keep you warm if it's too cold. S1: Of course! S2: Make sure you know all the safety rules. It's not safe to stand on a comet or get too close. There is always a strong wind in space. S1: I wont leave the spaceship except that i take photos S2: Photos Just think of the dust in the air. It will make taking photos very difficult. S1: Well, I'l take some anyway. S2: Watch out for the space wind! It can be very dangerous S1: Yes, // know that S2: Don't forget to watch the time as you leave the earth. please pay attention to everything your space guide says. Don't go off on your own. Look at your temperature on your spacesuit all the time. If it's too low you need to warm it up and if it's too high you need to cool it down. Anyway good trip! S1: Thank you. I will. Step v Speaking Task(Page67) The purpose of this task is to use the information the students have gained from the listening xt and reading passage in a new situation. they are going to interview the astronomer in our story, Li Yanping, for a newspaper So in pairs the need to work out some questions to ask him. Each of the pairs needs to think of three different questions. and try to find the Questions and answers: 1.What was the most unexpected thing you found out about black holes? The black hole threw out material as well as ate objects 2. How did you know you had got close to a black hole?
Watch out for… You mustn’t… T: Now discuss it in pairs. Then I will ask some pairs to read out their instructions. Sample dialogue: S1: I’m going to visit a comet. I’m leaving tomorrow. S2: How exciting! Please check that you have got the correct sort of spacesuit. You need the kind that will keep you warm if it’s too cold. S1: Of course! S2: Make sure you know all the safety rules. It’s not safe to stand on a comet or get too close. There is always a strong wind in space. S1: I won’t leave the spaceship except that I take photos. S2: Photos? Just think of the dust in the air. It will make taking photos very difficult. S1: Well, I’ll take some anyway. S2: Watch out for the space wind! It can be very dangerous. S1: Yes, I know that. S2: Don’t forget to watch the time as you leave the earth. Please pay attention to everything your space guide says. Don’t go off on your own. Look at your temperature on your spacesuit all the time. If it’s too low you need to warm it up and if it’s too high you need to cool it down. Anyway, have a good trip! S1: Thank you. I will. Step V Speaking Task (Page67) The purpose of this task is to use the information the students have gained from the listening text and reading passage in a new situation. They are going to interview the astronomer in our story, Li Yanping, for a newspaper. So in pairs the need to work out some questions to ask him. Each of the pairs needs to think of three different questions. And try to find the answers. Questions and answers: 1.What was the most unexpected thing you found out about black holes? The black hole threw out material as well as ate objects. 2.How did you know you had got close to a black hole?
3. What was the most frightening thing that happened to you on this journey? o You can see things disappear into what appears to be an empty space. thats a black hole. When the gravity of the black hole was pulling us to it's mouth, and then the spaceship moved round the hole and began to go faster and faster into it; I was terrified because i thought we would be eaten by the hole 4. Why did your watch move slower when your spaceship moved around the hole? Im not clear yet. 5. Have you found something new about black holes? Yes. i thought black holes only eat some objects, but in fact they also spit objects out Prepare for writing a passage about your idea or hopes for traveling in space
You can see things disappear into what appears to be an empty space. That’s a black hole. 3.What was the most frightening thing that happened to you on this journey? When the gravity of the black hole was pulling us to it’s mouth, and then the spaceship moved round the hole and began to go faster and faster into it; I was terrified because I thought we would be eaten by the hole. 4.Why did your watch move slower when your spaceship moved around the hole? I’m not clear yet. 5.Have you found something new about black holes? Yes. I thought black holes only eat some objects, but in fact they also spit objects out. Step VI Homework: Prepare for writing a passage about your idea or hopes for traveling in space