The total amount of energy in the universe never changes, but the amount of energy available for work at any given moment varies tremendously What best explains this change in available energy?
O A Energy can only be created through nuclear reactions
B. Energy is continually changing from one form into another
C Energy is always transferred as heat
OD Energy is always converted with 100 percent efficiency

Select the correct answer. anna will wear a black dress when she attends het cousin's wedding. which color(s) does the dress absorb? a. all colors b. no colors c. red and green d. white

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 ⇒

Which subatomic particle has a negative charge