Aprojectile is able to orbit the earth at what speed?

Simple machines can a. increase force only b. decrease force only c. increase or decrease force

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

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.