Aball took 0.45s to hit the ground 0.72m from the table. what was the horizontal velocity of the ball as it rolled off the table?

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight

How do cracks affect the rate of weathering?