The planet Krypton has a mass of

6.8 × 1023 kg and radius of 2.8 × 106 m.
What is the acceleration of an object in free
fall near the surface of Krypton? The gravitational
constant is 6.6726 × 10−11 N · m2
/kg2
.
Answer in units of m/s
2
.

A satellite moves in a circular orbit around
the Earth at a speed of 5.3 km/s.
Determine the satellite’s altitude above
the surface of the Earth. Assume the
Earth is a homogeneous sphere of radius
6370 km and mass 5.98 × 1024 kg. The
value of the universal gravitational constant
is 6.67259 × 10−11 N · m2
/kg2
.
Answer in units of km

1 answer

1. a pure application for Newtons gravational equation. Use it.
2. Fg=Fcentripetal
GMe*m/(re+h)^2 = m*v^2/r=m*(5300m/s)^2/(re+h)

solve for h

re+h=G*Me/25e6)^2
checkthat, solve forh