How much heat is required to warm 1.70 kg of sand from 28.0 ∘c to 100.0 ∘c?

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid

Based on the concept of the wave-like nature of light, huygens' theory of light postulates that the more light was "bent" by a substance the slower it would move while traversing across that substance. a) deflection b) interference c) refraction d) resonance

What is the orbital period of a spacecraft in a low orbit near the surface of mars? the radius of mars is 3.4×106m.