Agas is placed inside a very cold box. the gas molecules transfer heat to the walls of the box. which best describes what happens to the gas as it cools down? the gas molecules slow down, and some change phase to liquid. the gas molecules speed up due to collisions with the walls. the gas molecules vibrate around fixed positions. the gas molecules gain energy from the cold walls of the box.

Sound waves are mechanical waves in which the particles in the medium vibrate ina direction parrallel to the direction of energy transport. what is another name of the type of wave that transfers energy in this way?

The frequency of vibrations of a vibrating violin string is given by f = 1 2l t ρ where l is the length of the string, t is its tension, and ρ is its linear density.† (a) find the rate of change of the frequency with respect to the following. (i) the length (when t and ρ are constant) (ii) the tension (when l and ρ are constant) (iii) the linear density (when l and t are constant) (b) the pitch of a note (how high or low the note sounds) is determined by the frequency f. (the higher the frequency, the higher the pitch.) use the signs of the derivatives in part (a) to determine what happens to the pitch of a note for the following. (i) when the effective length of a string is decreased by placing a finger on the string so a shorter portion of the string vibrates df dl 0 and l is ⇒ f is ⇒ (ii) when the tension is increased by turning a tuning peg df dt 0 and t is ⇒ f is ⇒ (iii) when the linear density is increased by switching to another string df dρ 0 and ρ is ⇒ f is ⇒

World class speed skaters can skate a 3,000-m course in about 4 minutes.what is their average speed for this course? a. 12.5 m/sb. 1.33 m/sc. 1.25 m/sd. 13.3 m/s