ROCKET AND SATELLITE

 

LESSON NOTE

 

WEEK:

NAME: -                                                                                                       SUBJECT: - PHYSICS

DATE: -

CLASS: - S. S. 3                    DURATION: - 2 HRS 40MINS

TOPIC: - ROCKET AND SATELLITES 

INSTRUCTIONAL MATERIALS: -     cardboard showing the diagram of a model rocket.

REFERENCES BOOK: -    

1.     FARINDE O. E e tal, ESSENTIAL PHYSICS FOR SSS, Tonad Publishing Limited.

2.     M. W. ANYAKOHA (2011), NEW SCHOOL PHYSICS FOR SENIOR SECONDARY SCHOOLS, Africana first publishers.   

3.     INTERNET

PREVIOUS KNOWLEDGE: -     Students have been familiar with satellite dish of Tv

INSTRUCTIONAL OBJECTIVES: - At the end of the lesson students should be able to: -

                                                                                                                                                i.            Explain rocket and satellites.

                                                                                                                                              ii.            List the components parts of a model rocket

                                                                                                                                             iii.            Explain the launching of a multistage rocket

                                                                                                                                            iv.            Explain the component parts of satellite

                                                                                                                                              v.             state the uses of satellite

CONTENT: -

ROCKETS AND SATELLITES

Rockets and satellites are parts of the very important and exciting technological advance of the modern world. Rockets is used to to lift or transport the satellite to space.

The Chinese are believed to have invented the first rockets which they used as devastating weapon of war. They were described as 'arrows of flying fire' by historians.

 

 

 COMPONENT PARTS  OF ROCKETS

A rocket is an engine or instrument that produces a great power, more power for its size than any other kind of engine.

A model Rocket consists of 8 basic component:

1.       The body tube: This is a hallow cylinder to which all the other parts are attached.

2.       The launch lug: This is a narrow tube fastened to the side of the body tube. The launch lug guides the rocket and keeps it vertical during lift off.

3.       The fins: These are attached to the bottom part of the body tube just as fins are attached to a fish. They help the rocket to travel straight during  flight.

4.       The engine holder or engine mount: This is a ring cemented inside the bottom of the body tube of the rocket. It is constructed such a way that the rocket engine fits into the engine holder.

5.       The rocket engine: This is usually in the form of a tube and contains the solid fuel or propellant.

6.       Nose cone: This forms the top of a model rockets. Its tip has a rounded point that reduces the air resistance.

7.       The recovery device: is wired to return the rocket slowly to the ground after it has reached its highest point or maximum altitude called APOGEE. One such device is a parachute behind the nose cone.

8.       The launch system: This consists of a launch pad and an engine ignition system with a battery.

COMPONENTS PARTS OF A MULTISTAGE ROCKET

A multistage rocket consists of two or more section called stages. Each stage has a rocket engine and propellant. The entire rocket itself consists of rocket engine and nose cone.

 

A rocket travelling to space requires more than one engine. The reason is because it will require much large amount of fuel or propellant to gain the speed require to escape the Earth's gravity;  and this is not economically favourable. A multistage rocket can reach higher speed because it lightens its weight by dropping stages as it used up fuel or propellant. A system of two or more rocket engines called a multistage rocket is therefore employed.

The first rocket engine called 'first stage rocket' or Booster, launches the Rocket. After the propellant of this stage is used up, burnt or exhausted; the vehicle drops that section and uses the second stage, and the process repeats itself, after which the third stages comes into operation.

Another component part of the rocket is the nose cone. This is located at the pointed end of the entire structure. It is in the nose cone that the astronauts and payload stay during space travel. Pay load is the equipment carried by a spacecraft or rocket. It can be satellite or other research equipment.

LAUNCHING A MULTISTAGE ROCKET

The rocket is launched or sent off into space from a launch pad located at a special site called launch sites.

The rockets are prepared for launching in a step by step process called the COUNTDOWN. Each step is scheduled for a specific time during the countdown and the rocket is launched when the countdown reaches "zero". A hold may however occurs at any stage if the weather conditions are not conducive for launching the rocket.

The first stage fires to push the rocket to a considerable height. After which the engine disconnected and let down by means of parachutes or allowed to fall into the ocean at predetermined position and it is recovered for reuse. This make the rocket lighter. The second stage starts firing when the first stage is disconnected (or jettisoned). This increases  the  speed of the rocket when the fuel in the second stage finishes, it is jettisoned and may not be recovered like the first stage. This is because by now the rocket must have been very close to target orbit. At this point, the third stage fire the rocket into the target orbit.

FUNCTIONS OF ROCKETS

1.       Rocket carries astronaut to space to study the environment and the moon.

2.       Rocket carries robotic probes (i.e specialized equipment) to study other planets.

3.       Rocket carries artificial satellites such as weather satellite, Earth satellites, communication satellite etc.

4.       With rocket, portable laboratories can be carried to space to carry out some scientific researches which are imposible on earth's surface.

5.       Rocket engine can serve as a vehicle for carrying bomb to explode in an enemy territory.

USES OF ROCKETS

1.       Rocket are chiefly used for providing high speed transportation both the earth atmosphere and in space

2.       Bazooka(small rocket launcher carried by soldier) are used by the military or naval to send missiles to hit  enemies

3.       Rocket are used by scientist to explore the earth atmosphere

4.       Rocket provide the power to launch space craft into orbit i.e carrier rocket

5.       Rocket are used as distress signals from ships and airplane and from the ground

6.       Rocket are used in firework display

ROCKET PROPULTION

The force which moves a rocket comes from burning fuels. When the rocket fuels or propellants(e.g liquid hydrogen) enters the engine it mix with liquid oxygen in the right proportions and burns. During burning, ensuring gases expands and are forced out through the openings at the rear of the rockets. When this happens according to Newtons third law of motion (action and reaction are equal and opposite), the rocket is pushed in the opposite direction

SATELLTE

Satellite is any object that orbit or moves round a planet. There are two types of satellite;

1.       Natural satellite; E.g moon

2.       Artificial satellite; These are man made satellite. e.g weather satellite, communication satellite etc

DIFFERENCES BETWEEN ARTIFICIAL SATELLITE AND NATURAL SATELLITE

ARTIFICAL SATELLITE	NATURAL SATELLITE
i.            Is a device placed in orbits around the earth, moon or other planet	They are celestial bodies that orbits a planet or any other celestial body
ii.            Are man made	Formed by nature
3.            The electrical power required by satellite is provided by panels of solar cells and small nuclear reactor	They are opaque bodies with no light of their own. They received heat and light from sun
4.            Is made out of metals and electronics materials	Is made up of natural materials like rock, minerals, dust etc
5.            Can communicate with instruments of earth	Cannot communicate on earth or other planets

 

TERMS USED IN SATELLITE

1.       Parking orbits: is a temporary orbits used during the launch of a satellite or other space probe. A satellite is said to be in parking orbits if its period is exactly equal to the period of the earth, as it turns its own orbits which is about 24hrs

2.       Geostationary satellite: this is an earth orbiting satellite placed at an altitude of approximately 35800km directly over the equator. This satellite revolves in the same direction the earth rotates(west to east) in anti-clockwise direction.

    A  geostationary satellite always stay over the same place above the earth such a satellite is never at rest. Such a satellite appears stationary due to its zero relative velocity that place on earth.

    The orbit of a geostationary satellite is known as the parking orbit.

3.       Period of revolution of satellite: is the time taken to make one full orbit around an objects

COMPONENTS PART OF A SATELLITE

1.       Power: electricity is needed for the instrument and to enable the space craft directional control. Power is provided by solar arrays. Sometimes, the recently launched, saturn bound satellite, called cassini. Nuclear generators are used

2.       Communication: the satellite has to communicate with ground control so, direction and command can be send up and down to provide radio contract. Satellite have radio antenna .

3.       Guidance: star trackers and gyroscope help satellite align themselves in the right direction. This is common with astronomical satellite

4.       Scientific instruments: satellite have scientific instruments on them. Such instruments are cameras with diverse functions (as in the earth observation satellite), infrared sensors (as in weather satellite), radio antenna (as in communication satellite)

USES OF SATELLITE

1.       Communication satellite are used to relay or transfers telephone messages, radio and television signals across the world.

2.       Satellite made it possible to take pictures of places on the earth

3.       It is used in weather forecasting i.e in prediction of rainfall, snowfall, storm etc

4.       It is used to map piece of land in other to check erosion menace, pot holes on main road, topography, boundaries etc.

5.       Use for collecting information about other planets, stars and other celestial bodies

6.       Use for surveillance I.e spying and military intelligence

7.       Use for environmental monitoring.

PRESENTATION

Step I: The teacher introduces the new topic, rockets and satellite

Step II: The teacher explains the model rocket

Step III: The students chorus the 7 components of a model rocket

Step Iv: The teacher  explains satellite and its type.

Ste vi: The teacher lists some function and uses of satellites.                       

EVALUATION

The teacher evaluates the students by asking the following questions:

1.       Explain rocket and satellites

2.       List the components parts of a model rocket

3.       Explain the launching of a multistage rocket

4.       Explain the component parts of satellite

5.        state the uses of satellite

ASSIGNMENT

Read about Nigeria satellites.