Gravitation Practice
10 problems · instant feedback · full explanations
Gravity is an inverse-square force: F = Gm₁m₂/r². For orbits, gravity supplies the centripetal force — set them equal and solve.
Q1.
If the distance between two masses doubles, what happens to the gravitational force between them?
Multiple choice · Easy
Q2.
What is the gravitational force between Earth (6.0×10²⁴ kg) and a 70 kg person at Earth's surface (r = 6.37×10⁶ m)? Use G = 6.67×10⁻¹¹ N·m²/kg².
Numerical answer (N) · Medium
Q3.
Compute g at Earth's surface from G = 6.67×10⁻¹¹, M = 5.97×10²⁴ kg, r = 6.37×10⁶ m.
Numerical answer (m/s²) · Medium
Q4.
Approximately what is Earth's escape velocity?
Multiple choice · Easy
Q5.
A satellite orbits 500 km above Earth (r = 6.87×10⁶ m). Find its orbital speed using GM = 3.986×10¹⁴ m³/s².
Numerical answer (m/s) · Hard
Q6.
Why do astronauts feel weightless aboard the space station?
Multiple choice · Medium
Q7.
Changes in a gravitational field are felt instantly at any distance.
True / False · Hard
Q8.
The acceleration due to gravity decreases with altitude above Earth's surface.
True / False · Easy
Q9.
What is the gravitational force between two 1 kg masses 1 m apart? Use G = 6.67×10⁻¹¹ N·m²/kg². (Answer in newtons.)
Numerical answer (N) · Hard
Q10.
Kepler's third law relates a planet's orbital period T to its orbital radius r as:
Multiple choice · Medium