1.) How much power is required to lift a 50 Kg bell bar from the ground to shoulder height (1.7 m) in 0.2 seconds?

a. 4165 W

b. 425 W

c. 144.5 W

d. 167 W

e. 8330 W

2 Which of the following statements about lasers is CORRECT?

a. Spontaneous emission occurs when an electron jumps from a lower state to an excited state.

b. Stimulated emission occurs first, and light is emitted in all directions with all phases.

c. Spontaneous emission refers to the emission of light when a photon “tickles” the excited electron.

d. Once a some light is in the laser cavity, most of the emission is spontaneous from then on.

e. Stimulated emission refers to emission of light that is in phase with and in the same direction as the other light in the laser cavity.

3.) If a longitudinal wave has a frequency of 250 Hz and a wavelength of 0.5 m, calculate the wave's speed.

a. 2000 m/s d. 125 m /s

b. 500 m/s e. a longitudinal wave has no speed

c. 250.5 m/s

4.) Remember the in-class experiments we did with a kid's hot wheel track. If a 0.08 kg hot wheel car starts at the top of a 2 meter hill, what is its kinetic energy at the top of the next 0.7 meter hill? Neglect track friction.

a. 1.02 J

b. 1.6 J

c. 10.2 J

d. 3.2 J

e. 0.56 J

5.) A crane can pick up railway boxcars (45000 kg) from the dock to a ship's deck 25 m high in 6 seconds, how fast could it pick up an empty boxcar (15000 kg)?

a. 2 seconds

b. 18 seconds

c. 6 seconds

d. 3 seconds

e. 12 seconds

6.) From the diagram of energy levels for an electron in a particular element above, which statement is correct?

a) The photon given off when transition (a) is made will have more energy than that given off for transition (b).

b) The photon given off for transition (b) is the least energetic of the three.

c) The photon given off by transition ( c) is more red than that of transition (a).

d) The energy of photon from transition (b) will be equal to the energies of transition (a) and (c) added together.

e) The color of the photon given off in transition (a) will be the most blue of all three.

7.) If a box is sliding up a ramp at WalMart starts with 500 J of kinetic energy and it slows down to a stop with a potential energy of 450 J, what do you know about this situation?

a. The box's kinetic energy was completely converted into potential energy.

b. The box lost its potential energy.

c. The box gained more potential energy than it had in kinetic energy.

d. The box lost some of its mechanical energy to thermal energy (friction).

e. The box had a constant mechanical energy.

8.) Why do posters glow under illumination by black light?

a) The black light emits all colors of light and so the poster simply reflects that light.

b) A black light excites phosphors in the paint of the poster and they fluoresce (or glow).

c) A black light excites the dye molecules in the paint of the poster which then glow.

d) Posters are coated with a material which absorbs light in the infrared portion of the spectrum and then they re-emit light which we see.

e) Fluorescence is a process in which the heat from the lamp excites electrons in the poster paint into a highly excited state and then the electrons emit light as they drop to their lower energy states.

9.) Choose the correct statement from those listed below.

a. Transverse waves are created by displacing a slinky in the same direction as the wave travels.

b. When a person with a slinky makes a higher harmonic transverse wave of same amplitude of the original wave, it takes more energy.

c. When a piece of paper is placed on one ring of a slinky and you make a series of londitudinal waves with the slinky, the paper moves a distance A from its equilibrium position then moves back to its equilibrium position and stops.

d. The more energy you put into transverse waves of a particular wavelength, the smaller the amplitude of the resultant waves.

e. Constructive interference occurs when two waves that are out of phase with one another superpose

10.) If you increase the frequency of a light wave by a factor of 5, its wavelength will _______

a. decrease by a factor of 5

b. increase by a factor of 5

c. remain the same

d. increase by a factor of 25

e. you cannot tell because the speed is not given

11.) Wave A and Wave B interfere with one another. When Wave A and B have their left sides aligned, which resultant wave form is correct? Or choose e.