Page 6 - Spotlight A+ Physics Form 4.5

CHAPTER
3 Gravitation

Important Learning Standard Page
• Explain Newton’s Law of Gravitation. 66
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3.1 Newton's • Solve problems involving Newton’s Law of Gravitation for two
Universal Law static objects on the Earth; objects on the Earth’s surface; Earth 67
of Gravitation and satellites; Earth and Sun.
• Relate the gravitational acceleration, g on the surface of the Earth 68
with the universal gravitational constant, G.
• Justify the importance of knowing the values gravitational 69
acceleration of the planets in the Solar System.

• Describe the centripetal force in the motion of satellites and 70
planets system.
• Determine the mass of the Earth and the Sun using Newton’s Law 73
of Gravitation and centripetal force.
• Explain Kepler’s Laws. 74
3.2 Kepler's Laws • Express Kepler’s Third Law. 75

• Solve problems using Kepler’s Third Law. 76

• Describe how the orbit of a satellite is maintained at a specific 78
height by setting the necessary satellite velocity.
• Communicate on geostationary and non-geostationary satellites. 79
3.3 Man-made
Satellites • Conceptualise escape velocity. 80
• Solve problems involving the escape velocity, v for a rocket from
the Earth’s surface, the Moon’s surface, Mars' surface and the 81
Sun’s surface.

Important Formula and Tips

• Gravitational force / Daya graviti • Gravitational force, F = Gm m 2
1
• Universal gravitational constant r 2
Pemalar kegravitian semesta • Gravitational acceleration, g = GM
• Gravitational acceleration / Pecutan graviti mv 2 r 2
• Satellite / Satelit • Centripetal force, F = r
• Centripetal force / Daya memusat T 2 r 3
• Kepler's Third Law: 1 = 1
T 2 2 r 2 3
• Focus / Fokus 
GM
• Geostationary satellite / Satelit geopegun • Linear satellite speed, v =  r GMm
• Escape velocity / Halaju lepas • Gravitational potential energy, U = − r
• Gravitational potential energy 
2GM
Tenaga keupayaan graviti • Escape velocity, v =  r

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