Calculate the mass (in kg) of the Sun based on data for Venus's orbit.

How to tell if two objects are in thermal equilibrium 1.the objects have the same temperature 2.the objects are the same size 3.the objects are touching each other 4.the objects temperatures are changing

What is the orbital period of a spacecraft in a low orbit near the surface of mars? the radius of mars is 3.4×106m.

The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?