hw5a - HW#5a Page 1 of 4 For circular motion, we know that...

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HW#5a Page 1 of 4 For circular motion, we know that the total force in the radius direction pointing to the center equals to ma cp. All we need to do is to find all the forces at that position , add them in radius direction and solve the equation. .We should use v at that position too. Applies to all problems. 1, Ch. 6 Prob #46 - circ motion centrifuge To test the effects of high acceleration on the human body, NASA has constructed a large centrifuge at the Manned Spacecraft Center in Houston. In this device, astronauts are placed in a capsule that moves in a circular path of radius 15 m. If the astronauts in this centrifuge experience a centripetal acceleration 9 times that of gravity (or " 9 g's"), what must be the speed of the capsule? 2, Jill of the Jungle swings on a vine 6.5 m long. What is the tension in the vine if Jill, whose mass is 61 kg, is moving at 2.4 m/s when the vine is vertical? 3. Driving in your car with a constant speed of 12 m/s, you encounter a bump in the road that has a circular cross section, as indicated in Figure 6-35. If the radius of curvature of the bump is r = 35 m, find the apparent weight of a 67 kg person in your car as you pass over the top of the bump. Attention that a cp and the net force is pointing to center. Also the unit is kN, not N. Normal force is less than mg, the total acceleration is downward. That’s how the car “falls” (changes direction) after the bump.
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HW#5a Page 2 of 4 4. A 0.075 kg toy airplane is tied to the ceiling with a string. When the airplane's motor is started, it moves with a constant speed of 1.21 m/s in a horizontal circle of radius 0.44 m, as illustrated in Figure 6-40. Find the angle the string makes with the vertical and the tension in the string. Notice that the circular motion is in the horizontal plane. The center is at the center of that circle but not the point on the ceiling. The radius of this motion is the radius of that circle, not the length of the string. The acceleration and total net force is pointing to the circle center along the horizontal plane. It is important to
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This note was uploaded on 08/25/2010 for the course PHYS 111 taught by Professor Jamesm.lockhart during the Spring '09 term at S.F. State.

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hw5a - HW#5a Page 1 of 4 For circular motion, we know that...

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