Assignment:
Please show work and how you got the answer.
1.) A sound wave with a frequency of 250 Hz moves with a velocity of 340 m/s. What is the distance from one condensation to the next?
2.) The air temperature was 73.30 during a thunderstom and thunder was timed 6.09 after lightning was seen. How many feet away was the lightning strike?
3.) Sound from the siren of an emergency vehicle has a requency of 851.0 Hz and moves with a velocity of 344.9 m/s. what is the distance from one condensation to the next?
4.) Water waves are observes to pass under a brifge at a rate of one complete wave every 5.8s.
A) what is the period of these waves?
B) what is the frequency ?
5.) A soundwave in a steel rail of a railroad truck has a frequency of 649 Hz and a wavelength of 7.7m what is the speed of sound in this rail?
6.) A ship at sea sounds a whistle blast and an echo returns from the coastal land 16.8 s later. How many km is it to the coastal land if the air temperature is 25.2C ?
7.) A vibrating object produces periodic waves with a length of 45 cm and a frequency of 41 Hz. How fast do these waves move away from the object?
8.) Medical applications of ultra sound use frequencies up to 2.00 x 10^7 Hz. What is a wavelength of this frequency in 20C air?
9.) Is it possible for two people to simultaneously operate 850 W hair dryers on the same 120 V circuit without tripping a 15 A circuit breaker? Yes or no? Explain each dryer draws 8.50, 7.1, 3.5, or 4.7A of current, so two such devices will, will not cause a 15- A breaker to trip .
10.) Round final answer to nearest cent. What is the monthly (30 days) energy cost of leaving a 40-W bulb on continuously if electricity cost 10 cents per kWh?
11.) An automobile starter rated at 2.30 hp draws how many amps from a 12.0 v battery?
12.) An inflated rubber balloon is rubbed with a wool cloth until an excess of 1.00 x 10^5 electrons s on the balloon. What is the magnitude of the charge on the balloon?
13.) A ll.0 ? lightbulb is connected to a 12.0 V battery.
(a) What current flows through the bulb?
(b) What is the power of the bulb?
14.) An electric motor draws a current of 15.9 A in a 120 V circuit. What is the power of this motor in W?