Target Practice – Gravitation (20 Marks)

1. State Newton’s law of gravitation. (2)
   F = Gm₁m₂/r²
2. Write dimensions of G. (2)
   [M⁻¹L³T⁻²]
3. Why is g maximum at poles? (2)
   No centrifugal reduction
4. Expression for g at height h. (2)
   g = g₀(1 − 2h/R)
5. Define escape speed. (2)
   Minimum speed to escape gravity
6. Value of escape speed of Earth. (2)
   11.2 km s⁻¹
7. Why satellite energy is negative? (2)
   Bound gravitational system
8. Define weightlessness. (2)
   Net force zero
9. State Kepler’s 2nd law. (2)
   Equal areas in equal times
10. Time period of satellite near Earth. (2)
    ≈ 84.6 min