1.) The air temperature was 84.90°F during a thunderstorm, and thunder was timed 3.08 s after lightning was seen. How many feet away was the lightning strike?
2.) A sound wave with a frequency of 480 Hz moves with a velocity of 420 m/s. What is the distance from one condensation to the next?
3.) You see condensed steam expelled from a ship's whistle 8.33 s before you hear the sound. If the air temperature is 26.5°C, how many meters are you from the ship?
4.) A ship at sea sounds a whistle blast, and an echo returns from the coastal land 18.6 s later. How many km is it to the coastal land if the air temperature is 13.7°C?
5.) (Has two parts)
vair = 331 m/s
vrail = 5,940 m/s
Compare the distance traveled in 9.04 s as a given sound moves through
(a) air at 0°C and
(b) a steel rail.
6.)( has four parts) The following sound waves have what velocity?
(a) Middle C, f = 256 Hz and λ = 1.34 m
(b) The note A, f = 440.0 Hz and λ = 78.0 cm-
(c) A siren with f = 736.0 Hz and λ = 46.6 cm
(d) A note from a stereo with f = 2,600.0 Hz and λ = 13.2 cm
7.)(has two parts) A water wave has a frequency of 5.0 Hz and a wavelength of 5.0 m.
(a) What is the period of these waves?
(b) What is the wave velocity?
8.)Water waves are observed to pass under a bridge at a rate of one complete wave every 4.6 s.
(a) What is the period of these waves?
(b) What is the frequency?
9.)The lower frequency limit of hearing for a particular human being is 25.0 Hz. What is the corresponding wavelength for this frequency if the air temperature is 18.2°C?λ = m
10.)The distance between the center of a condensation and the center of an adjacent rarefaction is 76.30 cm. If the frequency is 218.5 Hz, how fast are these waves moving?
11.)A small radio operates on 120.0 V and has a resistance of 95.0 Ω. At what rate does the radio use electric energy?
12.)A wire carries a current of 1.8 A. At what rate is the charge flowing?
13.) (has three parts) An average-sized home refrigeration unit has a 1/5-hp fan motor for blowing air over the inside cooling coils, a 1/3-hp fan motor for blowing air over the outside condenser coils, and a 2.00-hp compressor motor.
(a) All three motors use electric energy at what rate?
(b) If electricity costs $0.15/kWh, what is the cost of running the unit per hour?
(c) What is the cost for running the unit 12 hours a day for a 30-day month? (Round final answer to the nearest cent.)
14.)Is it possible for two people to simultaneously operate 1,800 W hair dryers on the same 120 V circuit without tripping a 10 A circuit breaker? Explain.
Each hair dryer draws ___ A of current, so two such devices cause a 10-A breaker to trip.
15.)An electric current through a wire is 7.68 C every 2.75 s. What is the magnitude of this current?
16.) ( has two parts) A step-up transformer has a primary coil with 125 loops and a secondary coil with 2,250 loops. If the primary coil is supplied with a household current of 120 V and 25 A, (a) what voltage is produced in the secondary circuit?
(b) What current flows in the secondary circuit?
17.)A rubber balloon has become negatively charged from being rubbed with a wool cloth, and the charge is measured as 1.00 × 10-14 C. According to this charge, the balloon contains an excess of how many electrons?
17.)There is a current of 0.86 A through a lightbulb in a 12 V circuit. What is the resistance of this lightbulb?
18.)An inflated rubber balloon is rubbed with a wool cloth until an excess of 1.00 × 1010 electrons is on the balloon. What is the magnitude of the charge on the balloon?
19.)Two 45.0-Ω lightbulbs are connected in a 24.0-V series circuit. What is the power ofOne bulb (as described above) in a simple circuit?
One bulb in a pair of identical bulbs (as described above) connected in a 120.0 V series circuit?
Thus, two lamps connected in a series circuit, as compared to one lamp in a simple circuit, increases decreases the current by one fourth one half three fourths and decreases increases the voltage byone fourth one half three fourths , resulting in the power for each lamp. (choose one from the underlined)
20.)Round final answer to the nearest cent.A 2,750-W hair dryer is operated on a 120-V circuit for 23 min. If electricity costs $0.22/kWh, what was the cost of using the blow dryer?
21.) ( has two parts) One rubber balloon with a negative charge of 5.60 × 10-14 C is suspended by a string and hangs 2.40 cm from a second rubber balloon with a negative charge of 2.40 × 10-12 C.
(a) What is the direction of the force between the balloons?
( choose one from the underlined) Repulsive, neutral attractive
(b) What is the magnitude of the force?