Calculating masses and cosmic velocities
Answers are for parents and teachers.
1
An orbit is 24,000 km long and the speed is 8 km/s. How many seconds does one turn take?
3000
2
A moon has a = 4 · a_Moon and T = 4 · T_Moon. How many times heavier than the Earth is the planet? (4³ : 4²)
4
3
How many seconds does a body at 3 km/s take to cover 6000 km?
2000
4
Why does a body launched near the Earth at less than 7.9 km/s fall back?
Gravity curves its path back; without enough horizontal speed the orbit intersects the Earth’s surface.
5
Why is Jupiter’s escape velocity much larger than the Earth’s?
Jupiter is far more massive (≈ 318 Earth masses), so its gravity is strong.