The alignment of the Sun, Earth and Moon can produce shadows on the Earth or Moon resulting in:

very long nights

equinox

solar and lunar eclipses

longer seasons

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?

Athe top of a hill, an athlete on a skateboard has x joules of mechanical energy. how much mechanical energy will she have at the bottom of the hill? ignore the effects of friction.