James is planning a science fair project on sound waves. He places an alarm inside a jar which he can remove the air from. Before he removes the air, he can hear the alarm ringing. After he removes the alr, he cannot hear the
alarm ringing. What condusion can you draw from this experiment?

A. Sound waves can travel in a vacuum
B. Sound waves are transverse waves and are loud
C. Sound waves cannot travel through a medium
D. Sound waves require a medium to travel through

The step-down transformer gives a current of 10a at 24v if the primary voltage is 240v calculate the 1_primary current 2_the power input 3_the power output

Describe different biomes. what are some adaptations that organisms (plants or animals) must have to live in each biome?

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 ⇒