Motion of satellites

by Kundyz Taimanova

​Class: 9 th

​Subject: physics

​Chapter: Satellites

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​ ^3.12

​In this lesson you will learn to:

​- use formula of orbital speed of satellite for problem solving

​- compare different orbits of satellites

​- calculate parameters of motion of objects moving in gravitation field

​Look at the photos. What connects them? (Storm, phone call get lost in the city)

​Why do we use satellite dishes?

​Vocabulary

​satellite - серік, спутник

​communication - байланыс, связь

​to revolve - айналу, вращаться

​possible - болуы мүмкін, возможный

​outcome - нәтиже, результат

​computation - есептеу, вычисление

The Earth's escape velocity

​https://bilimland.kz/en/courses/physics-en/mechanics/dynamics/lesson/the-movement-in-space

​The lowest velocity which a rocket needs, in order to escape the gravitational pull of the Earth, is called the Earth's escape velocity (or second cosmic velocity).

​The main parameters of computation are:

1. Speed of satellite: V [m/s]

2. r- radius of rotation r=R+h [meters]

3. M- mass of a plannet [kg]

4. ​G - gravitational constant G= 6.67*10^-11 Nm²/kg²

​A graph

​The first rocket that reached the Earth’s escape velocity was Luna 1 – a rocket launched on 2nd January 1959 by the Russians. It passed the Moon at a distance of a few thousand kilometres and flew further to become the first man-made object orbiting the Sun.

Exercise 1

A communication satellite is orbiting the Earth 36000 km above sea level. Knowing that the radius of the Earth is 6400 km, its mass is 6*10²⁴ kg and the universal gravitation constant is G = 6.67 * 10^{- 11} Nm²/kg² find

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​a) the period of the sattellite?

​b) the tangential speed of the sattellite? (Take п= 3.14)

​Let's end today the lesson

​1. What determines the satellite's first cosmic velocity?

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​2. What physical quantity can be determined by the formula of the first cosmic velocity?

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​3. How does the speed of a satellite moving in a circle change if the distance to the center of the planets increases by 4 times ?

​Homework: Literacy

​Learn basic definitions using the link

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​THANK YOU FOR ATTENTION