UNIT 12. A WORLD IN MOTION

Transcription

1 NAME: UNIT 12. A WORLD IN MOTION 1. INTRODUCTION. BRAINSTORM Think and discuss about these questions: a) Are your rucksacks moving at the moment? b) Is a rucksack into a car moving? Use these sentences: I think that it depends on the If we use a frame of reference then In my opinion, the rucksack is/is not. Vocabulary Motion Rest.... Trajectory... Frame of reference.. Distance.. Time. Speed.. Path.. Arrow.... 1

2 1.- ARE WE MOVING? When you are travelling by car or bus, it seems that the Earth does not move. But our planet travels 30 km per second around the Sun. To observe the movement of an object we must have a reference point. Frame of reference. Is the point of view, from which we observe an object Movement. Is the change of position of an object in relation a fixed point in space. For example a train which advances while the countryside does not move. Trajectory ( path ). Is the imaginary line described by an object in movement. If the line described is straight, the trajectory is called rectilinear; if the line is curved, the trajectory is called curvilinear; if it is a circle, the trajectory is called circular. Activity 1.- Draw the trajectories of the following movements and classify them into one of these groups: a circunference, a parabola or an irregular curve. The Earth orbiting the Sun A motorbyke driving in a race The movement of the ends of the hands of a clock 2

3 Activity 2.- Work in pairs: Two friends are travelling in a cruise. They are having breakfast in the dining cruise and one of them says: I will meet you tomorrow at the same place. Then, the other friend answers: It is impossible, because the cruise is moving According to the definitition of Frame of Reference, Who is right? 2.- SPEED AND VELOCITY Although speed and velocity are often used interchangeably in everyday life, they represent different quantities in physics. Speed is a measurement of how fast an object moves relative to a reference point. It does not have a direction and is considered a magnitude or scalar quantity. Speed can be figured by the formula: Speed= Distance Time Speed is Distance over Time There are two common units for speed, you should realise that they re all kind of the same: distance unit per time unit. metres per second----- m/s kilometres per hour----km/h In physics, velocity is the measurement of the rate and direction of change in position of an object. It is a vector quantity; both magnitude and direction are required to define it. For example, "5 metres per second" is a scalar and not a vector, whereas "5 metres per second east" is a vector. 3

4 4.- TYPES OF MOVEMENTS There are two types of movements according to the variation of speed: Uniform movement Non uniform movement or varied movement - Uniform movement: When equal distance is covered in equal interval of time. In this case, the bodies are moving with constant speed. - Non Uniform movement: When unequal distances are covered in equal interval of time. In this case, the bodies are varying speed. Activity 5 True or false? Rewrite the false sentences correctly Uniform rectilinear movement is a trajectory in the form of a straigh line which has a varied speed. True/False 4

5 Velocity and speed are the same concepts. True/False The distance between two points is equal to the speed over the time. True/False In talking about movement, it is not so important to indicate your point of reference True/False Activity 6 You are going to work with your partner. Read the following text and discuss the questions with him/her. The speed depends on the following factors: the state of the road, traffic conditions, climate conditions and the presence of animals. Each country establishes the speed limit it considers appropiate for each kind of road. For example, in Spain in built-up areas the maximum speed limit is 50 km/h. However, in some countries, like Germany, there is no speed limit on motorways a) What the speed limit is in the built-up areas in Spain? And on motorways? Do you think these are appropiate speed limits? Gives 5

6 examples to support your answers. b) What do you think about no speed limit on motorways in Germany? Do you agree? Do you think is a good measure? c) Do you know any climate conditions that increase the risks of accidents? 5. NEW ZEALAND DRIVING RULES A) Speed Limits in New Zealand 50 km/h (urban) 70km/h (urban) 100 km/h (open road) Open Road (100km/h) B) New Zealand Traffic Signals Reduce speed to 20km/h Reduce speed to 20km/h when passing a stationary school bus C) New Zealand Roads Signs Give way to all vehicles except those that have stopped at a Stop sign. You must stop. Stay stopped and give way to all other vehicles. Follow the 6

7 Keep Left No Left Turn No U-Turn Look out for Children Greasy Surfarce Slips Metal Surface Road Narrows Road Works Activity 7 Compare these traffic rules in New Zealand with the rules in Spain. 1. Vehicles in the NZ drive on the left hand side of the road. 2. Driving licences may be obtained by any NZ resident over the age of ROAD TRAFFIC SAFETY - Speeding (driving too fast) is a problem. In the case of traffic, speeding has two dangerous consequences: -It increases the risk of having an accident. -An accident that occurs when a car or a bicycle is travelling at high speed will generally have worse consequences for the passengers or pedestrians (because they are hit with more force). - It is very important for everybody to learn traffic rules and traffic signs, so we can prevent traffic accidents. The users of a road include pedestrians, cyclists, motorists, their passengers, and passengers of on-road public transport, mainly buses. 7

8 When we are pedestrians, it is really important to know some basic rules of the road: A) When you cross the road 1) Use always zebra crossing or traffic lights 2) Don t use your mobile phone or send a text message 3) Don t listen to music 4) Don t chat to your friend 5) Be careful! B) When you ride your bike 1) Wear a cycle helmet 2) Wear a reflective vest 3) Use lights in the dark 4) Be careful! 8

9 FINAL TASK DO WE RESPECT TRAFFIC REGULATIONS? Ask your family and people who have a driving licence this questionnaire. Then, write the answers. 1.- Do you always respect the speed limit in built-up areas? Do you know the speed limit? 2.- Do you always respect the speed limit on motorways? Do you know the speed limit? 3.- Do you always use your indicator when you are going to change lanes or turn? Do you think it is important to use it? 4.- Do you keep the minimum safety distance? 5.- Do you double-park? Why? 6.- Do you respect traffic lights? 7.- Do you always respect zebra crossings? 9

10 A WORLD IN MOTION SELF-ASSESSMENT CHART Match one of these options: YES, NO AND NOT YET I CAN Identify scientific vocabulary YES NO NOT YET Take notes from a listening Find valuable information from different sources Describe images and pictures Prepare and present a presentation in the class I KNOW Explain the following terms: frame of reference, movement and trajectory The difference between speed and velocity The two types of movements The most common traffic rules The main consequences of speeding I Pay attention in class Try to participate every day, communicating in English Do my homework Hand in my writings neatly and on time Can work in a team Suggestions to improve my learning process: