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F = ma

Fd = W

KE = 1/2MV2

PE = mghg= 10 m/s2

W=KE+PE

Short answer/essay - SHOW YOU WORK! ! !

27.! How much Potential Energy is gained by to lifting 50 kg a distance of 6 m? (5points)

28.! How much work is done to lift a 50 kg object a distance of 6 m? Why, prove withone of the equations above (5 points)

29.! A rock (m = 250 kg) is located 50 m above the ground, how much PE does ithave? (5 points)

30.! The same rock has fallen to the ground, What is the rocks kinetic energy just be-fore it hits the ground? (5 points)

Name _______________________________________

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40.! What causes centrifugal force? Explain(5 points)

41. If you lose your grip on a rapidly spinning merry go round and fall off, in which direc-tion will you fall, A, B or C? Explain (5 points)

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Name _______________________________________

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75.Draw a sine curve with three complete wavelengths. Indicate the undisturbed posi-tion, amplitude, wavelength, crest and trough. (10 points)

Equations

Frequency =f= cycles/time Period = T = time/cycle

Speed = wavelength x frequency = distance/time

76.Find the frequency of vibration of a wire that moves back and forth 15 times during 3 sec-onds. (5 points)

77. Find the speed of a wave with a frequency of 100 Hz and a wavelength of 2.5 m (5points)

78. A wave vibrates up and down three times a second and travels a distance of 120 min three seconds. What is the frequency and speed of the wave? (10 points)

Name _______________________________________

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79.Circle yes or no (1 point each)

a.Can all waves exhibit diffraction? yes no

b.Can all waves exhibit interference? yes no

c.Can all waves exhibit doppler effect? yes no

d.Explain your answers (2 points)

HINT - Equations will work to answer the next two questions

80. How does the speed of a wave relate to its frequency and wavelength? (5 points)

81.How does the frequency of a wave relate to its period? (5 points)

82.What determines the speed of a wave? (5 points)

83.Does the medium travel with the wave? If yes how, if no, what does travel? (5 points)

Name _______________________________________

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93.What is the source of all sounds? (5 points)

EquationsFrequency = f= cycles/time Period = T = time/cycle

Speed = wavelength x frequency = distance/time

94.How does the speed of sound in air compare with the speed of sound in water. (5points)

95. What is the beat frequency when a 256 Hz tuning fork and a 259 Hz tuning fork aresounded together. (5 points)

96. What type of wave is a sound wave? (5 points)

Name _______________________________________

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Equations

Distance = speed x time

Wave speed = wavelength x frequency

Speed of sound is 340 m/s

97. You watch a distant farmer driving a stake into the ground with a sledgehammer. Hehits the stake at a regular rate of one stoke per second. You hear the sound of the blowsexactly synchronized with the blows you see. And then you hear two more blows afteryou see him stop hammering. Calculate ( show your work) how for away is the farmer(You may have been using binoculars the see the farmer). (10 points)

Name _______________________________________