Questions

1.

True of false: we feel a gravitational force of attraction towards the Earth, but no electrical attraction because gravity is in general a much stronger force.

2.

If the Earth were suddenly to shrink to half its radius, would your weight increase, or decrease? By how much?

3.

Which has a greater escape velocity at the surface of the Earth (neglecting air resistance), the space shuttle, or a tennis ball?

4.

Would a planet move faster in its orbit around the Sun near its perihelion, or near its aphelian?

5.

True or false: in Einstein's theory of gravity, the space around the Earth is curved, so that satellites travelling along parallel paths can actually collide with each other.