A mass on a spring goes from its highest point to its lowest point and back to the highest point 20 times a second. The frequency of the oscillation is
A. 20 Hz
B. 0.05 Hz
C. 40 Hz
D. 0.025 Hz
2. Light comes in hundreds of wavelengths. Why do we say that three primary colors (wavelengths) of light can make all colors?
A. Any real dye absorbs a range of wavelengths
B. The human eye can only distinguish three colors
C. The human eye has three kinds of cones, which can detect and blend three particular wavelengths
3. Light is different from sound in that
A. Lights exhibits polarization
B. Light can travel in a vacuum
C. Light has such a small wavelenth that we don't ordinarily notice it bending around corners
D. All of the above