Water evaporators is this a physical change or a chemical change?

Select all of the following that are equal to an impulse of 20 unitsa) force= 5, time= 5.5b) force= 25, time= 0.8c) force= 0.1, time= 200d) force= 10, time= 2(its b, c, and d)(also in order to find answer they have to add to get the unit)ex= 25x.8=20 or .1x200=20

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.

Convection occurs when thermal energy is transferred by the movement of