A: What would be the length of one day if the Earth spun so fast that bodies floated at the equator? Radius of the Earth being about 6380 km?
B: If the radius of Earth were to shrink by 1.0%, its mass remaining the same, would the acceleration due to gravity g on the Earth's surface increase or decrease (why), and by what percentage?
C: There are two solid steel spheres. Sphere 1 has one third of the radius of sphere 2. By what factor does the moment of inertia I_2 of sphere 2 exceed the moment of inertia I_1 of sphere 1?