Two planets have equal masses, are 1.0*1010 m apart, and have a gravitational force of 0.5 N towards each other. What are their masses?

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?

Suppose that three astronomical objects, 1, 2, and 3 are observed to lie on a line, and the distance from object 1 to object 3 is d. object 1 has four times the mass of object 3, and seven times the mass of object 2. find the distance between objects 1 and 2 for which the net force on object 2 is zero.

In which of these cases are the two wave points considered to be in phase with each other?