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Unformatted text preview: NAME ____________ 6/18/08
PHY 203 Exam #2 Prof. Rollino 1) The coefﬁcient of friction between your tires (your car‘s tires of course) and concrete is 0.75
A. What is the angle of incline of the steepest hill the car can park on without sliding down the hill?. 9. : (27/4,) .—.— 34.9 ° . From an initial speed of 35.0 m/s, calculate the shortest distance in which the car can stop. (g £3 “rally/"Ia : [7114 M1 ”21 : “ Z/ASS (57‘)
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C. At 35.0 m/s what is the shortest radius in which the car can turn without skidding? Relgi 35L _ /6¥
”$3  (2:)(91?) ‘ /éé.1z M (15)) 2) A horizontal rotating turntable has an outer radius of 25.0 cm. A small block is placed on the edge of the turntable
and the turntable is made to spin faster and faster. When the turntable reaches 35.0 revolutions per minute, the block flies off the turntable. Draw a free body diagram and calculate the coefficient of static friction between the
turntable and the block. 1“ .5
.,—> : 939?”? ﬂ; 2 .391 W T 3) A 80.0 kg fireman climbs a ladder 15.0 meters high in 10.0 seconds at a constant acceleration.
P a. What force must he exert on the rungs to do this? r :2: = 2.93 P=Pv/9**‘”A/
M b. How much work hasohe done? Zeglect any {rigtion’r ) S P 2 fog
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F [NV/MK m/ 2 /2/20\T 5EFJé/wivi =é§)[goY3)z 7f 3%) \ c. What is his average power output? P (/2/20 a /2/2 14/ 14% IO d. What is his instantaneous power when he is two—thirds the way up the ladder? A)" ‘3 z 65>(m) ~21 ,m :(Eof)<2\w9)  /9‘;¢9vz/ raw/7
d. What is his potential energy at the top of the ladder, assuming Ep at the bottom of the ladder is zero? 5,3: #134 7 (PMWX/a‘)  mwf (15) 4) A 8.00 kg block is pushed against a spring (k = 3000N/m) so that the spring compresses 0512 meters. The block,
when released, slides along a smooth, frictionless, horizontal surface ,2.50 meters long, and comes to an inclined plane of 30°. The inclined plane is also smooth. For each of the following problems include an energy chart in your
solution. a. How far up the plane will the block slide before reversing direction? k
y 3 ._" 5r U/ gaimjuwa o A L: KA ‘: (3000 611
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3 . 5‘an b. Rework part_ a but now the inclined plane and horizo tal surface have a coefficient of kinetic friction of.1. ‘l .
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: g 1% M (441 20 ( lX?)(1&)[email protected]+ (9X1 805qu0 ‘ i 5) NASA has sent a satellite to a distant planet and put the satellite In an orbit of with a radius 7000 km. The satellite takes 5 00 hours to complete its orbit. 3w 7— ¥ (0 )3 2 it
A. Calculate the mass of the/planet. 'G’Rw .. 7‘ IO 5 Km”
w: ME“) 6677’104/3/
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R 11‘  I 2 9? )r 03/ B, Calculate the centripetal acceleration of theé sg‘tellite .th Rec = ?X/0 IZW>LM ,XS/B/w/{z (10) Mfr/o" 6) A 40.0 kg child on a playground swing is pulled back so that the chains supporting the swing make an angle of 30°
with the vertical. The ropes are 4.0 meters long. She is then pushed with an initial speed of 1.50 m/s a. With what speed will she pa .. e lowest point of her ride. , ~
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$ v~ (. M \12696‘)(1/){(4030‘Hh3): 3¥%/Zf b. What will be the tension in each of the two chains as she passes throu h the lowest point?
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7) Two 50 kg blocks are arranged as in the diagram They are connected by a light flexible cord which passes over a wheel of negligible friction. Bzoth surfaces are frictionless. When released from rest the horizontal block experiences
an acceleration of 2 60 m/sz. Calculate the angle the inclined plane makes with the horizon W
A. ...
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 Fall '08
 James
 Physics

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