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Ken Cheney
10/29/2005
4:54/C0
Physics 31A Test Three
1. TARZAN
Tarzan grabs a 35 meter long vine and swings down from his tree.
The vine originally makes an angle of 32 degrees with the vertical.
How many meters per second is Tarzan going as he falls off at the
bottom of his swing?
SQR(2*9.8*35*(1-COS(32)))
a. 3.73, *b. 10.2, c. 16.3, d. 25.1, e. 34.3
2. UNIVERSAL FALLING
Show why everything falls with the same acceleration.
3. DURIVE CENTRFICAL ACCELERATION
Durive centrifical acceleration any way you want. Explain lots!
4. FRICTION AND BURGER KING
What is the maximum velocity (m/s) you can go to make a turn of
7.6 m radius if the coefecent of friction is .37 and g on the planet is
12 m/s/s?
SQR(.37*12*7.6)
a. .821, b. 2.48, c. 3.85, *d. 5.81, e. 304
5. LITTLE G
What would g be at a distance of 4.9 Earth radi away from the
Earth's center? m per second squared
9.8/4.9/4.9
a. .155, *b. .408, c. .546, d. 2.08, e. 3.18
6. KE DERIVATION
Durive KE=1/2 m v x v for a variable force which accelerates a
mass m to a velocity v starting from rest. Explain carefully. If you
have any constants of integration explain how you deal with them.
7. TRAINS AND ACCELERATION
The villan is escaping with your loved one on a train and left .99
minutes ago. You instantly calculate that the engine has a mass of
79,000 kg and a pull of 25,000 newtons, you see it is pulling 10 cars
of 12,000 kg each. Your loved one has put on the brakes of the last
car, mu=.1. How far away, m, is the train when you arrive?
(25,000-.1*12,000*9.8)*(.99*60)**2/(2*(79,000+10*12,000))
a. 25, b. 55.6, c. 77.1, *d. 117, e. 16,600
Shall I go on? [YES]
Shall I print the tests on the:
Terminal (T), Line printer (L), Both (B), or Neither (N)? t
Shall I print the key on the:
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Touch RETURN to continue.
Ken Cheney
10/29/2005
4:54/C1
Physics 31A Test Three
1. TARZAN
Tarzan grabs a 24 meter long vine and swings down from his tree.
The vine originally makes an angle of 41 degrees with the vertical.
How many meters per second is Tarzan going as he falls off at the
bottom of his swing?
a. 2.63, b. 5.68, c. 7.72, d. 10.7, e. 33.8
2. UNIVERSAL FALLING
Show why everything falls with the same acceleration.
3. DURIVE CENTRFICAL ACCELERATION
Durive centrifical acceleration any way you want. Explain lots!
4. FRICTION AND BURGER KING
What is the maximum velocity (m/s) you can go to make a turn of 10
m radius if the coefecent of friction is .54 and g on the planet is 21
m/s/s?
a. 3.04, b. 7.24, c. 10.6, d. 347, e. 462
5. LITTLE G
What would g be at a distance of 1.8 Earth radi away from the
Earth's center? m per second squared
a. .467, b. 1.04, c. 1.72, d. 2.18, e. 3.02
6. KE DERIVATION
Durive KE=1/2 m v x v for a variable force which accelerates a
mass m to a velocity v starting from rest. Explain carefully. If you
have any constants of integration explain how you deal with them.
7. TRAINS AND ACCELERATION
The villan is escaping with your loved one on a train and left .89
minutes ago. You instantly calculate that the engine has a mass of
110,000 kg and a pull of 22,000 newtons, you see it is pulling 10 cars
of 12,000 kg each. Your loved one has put on the brakes of the last
car, mu=.1. How far away, m, is the train when you arrive?
a. 22.1, b. 63.5, c. 14,300, d. 26,300, e. 37,600
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ANSWERS FOR Physics 31A Test Three ON 10/29/2005
PRINTED FOR Ken Cheney ON FRI, OCT 28 AT 4:54/C PM
Physics 31A Test Three - Ken Cheney - V. 4:54/C KEYY 2 PAGE 2
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