1. The magnitude of the gravitational force, F, between two masses,

m₁ and m₂, which are a distance r apart, is given by the formula

F = G m₁ m₂ /r², where G is a universal constant.

1. What are the SI units of G?
2. If you are given the data that a 5.98X10²⁷ g planet 6.4X10⁸ cm from a 2X10⁵g mass professor attracts him with a force of 2.0X10⁸ g cm s^-2,

find G in SI units to the correct number of significant digits.