7. Which phase changes require a gain of energy (heat)? a. melting and freezing
b. sublimation and vaporization
c. vaporization and condensation
d. sublimation and deposition

Aquantity of gas has a volume of 1.5 m3 and an absolute pressure of 95 kpa. when the gas is compressed to a volume of 0.5 m3, what is the new absolute pressure of the gas? (assume that there’s no change in temperature.)

A-of 75 cm by cm by 17.5 cm up. of is 2 kg a , in ,if it is in , kg/?

Which of the following are properties of mechanical waves? check all that apply ⭕️ particles of the medium move back and fourth, but do not move with the wave. ⭕️ the particles of the medium always move parallel to the wave motion. ⭕️ wave motion begins with a disturbance in the medium. ⭕️ waves transport energy from a source outward, away from the source.