Angela sees a puzzle that uses a board with 20 holes drilled into it. there are 18 pegs in the holes, and the goal of the puzzle is to move the pegs by hopping them into the open holes until both holes are at one end of the board. how could angela use the puzzle to model semiconductors? a. as an n-type semiconductor with the pegs representing electrons and the holes representing positive charges b. as an n-type semiconductor with the holes representing electrons and the pegs representing positive charges c. as a p-type semiconductor with the pegs representing electrons and the holes representing positive charges d. as a p-type semiconductor with the holes representing electrons and the pegs representing positive charges

Acommercial passenger jet can travel up to 970 km/hr at an altitude of 30,000 feet. at this speed, how long will it take the jet to travel 1,865 kilometers? a. 2.3 hrs b. 1.9 hrs c. 1.7 hrs d. 1.5 hrs

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 of these statements is true? a. quarks pair with leptons to form protons and neutrons. b. quarks pair with bosons to form photons. c. quarks pair with photons to form protons and neutrons. d. quarks pair with other quarks to form protons and neutrons. e. quarks pair with electrons to form protons.