Atrain station bell gives off a fundamental tone of 500 hz as the train approaches the station at a speed of 20 m/s. if the speed of sound in air is 335 m/s, what will be the apparent frequency of the bell to an observer riding the train?
a. 532 hz
b. 530 hz
c. 470 hz
d. 472 hz

1. a camcorder has a power rating of 19 watts. if the output voltage from its battery is 7 volts, what current does it use?answer units 2. a 1.5m wire carries a 6 a current when a potential difference of 57 v is applied. what is the resistance of the wire? yourunits 3. a clothes dryer uses about 2 amps of current from a 240 volt line. how much power does it use? yourunits 4.

Why do astronauts in the space shuttle weigh less?

Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness