1) Resonance occurs with forced vibration that requires the

a. least amount of energy input.

b. maximum amount of energy input.

c. matching of wave amplitudes.

d. matching of constructive and destructive interference.

e. minimum beat frequency.

2) X-rays are emitted by way of

a. ionizing radiation.

b. transitions within an atom's innermost electrons.

c. transitions within the atomic nucleus.

d. none of the above

3) The speed of a sound wave in air depends on

a. its frequency.

b. its wavelength.

c. air temperature.

d. all of the above

e. none of the above

4)When a load is placed on a properly arched structure, compression

a. weakens the structure.

b. strengthens the structure.

c. neither of these