A0.75 kg teddy bear is nudged off a window sill and falls 2.05 m to the ground. what is its kinetic energy at the instant it hits the ground?

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.