Question

8. A spool of thread has an average radius of 2.00 cm. If the spool contains 75 m of thread, how many turns of thread are on the spool? "Average radius" allows us to not need to treat the layering of threads on lower layers. a. 322 b. 597 c. 150 d. 100 9. In order for a satellite to be geosynchronous, its orbit must: a. be over the equator. b. be over a single longitude. c. emit television signals. d. go over the North and South Poles. 10. An asteroid is in orbit at 20 times the earth's distance from the Sun. What is its period of revolution? a. 17 years b. 89 years c. 112 years d. one fourth year 11. A cylindrical space colony 6 km in diameter and 50 km long has been proposed as living quarters for future space explorers. Such a habitat would have cities, land and lakes on the inside surface and air and clouds in the center. All this would be held in place by the rotation of the cylinder about the long axis. How fast would such a cylinder have to rotate to produce a l-g gravitational field at the walls of the cylinder? a. 0.042 rad/s b. 0.057 rad/s c. 0.098 rad/s d. 0.033 rad/s 12. A satellite is in a circular orbit about the Earth at a distance of one Earth radii above the surface. What is the speed of the satellite? (The radius of the Earth is 6.4 x 106m, and G = 6.67 x 10-1l N-m²/kg.) a. 7899 m/s b. 5592 m/s c. 3407 m/s d. 12,098 m/s 13. A roller coaster, loaded with passengers, has a mass of 4000 kg: the radius of curvature of the track at the bottom point of the dip is 15 m. If the vehicle has a speed of 12 m/s at this point, what force is exerted on the vehicle by the track? (g = 9.8 m/s) a. 0.44 x 10'N b. 7.76 x 10'N c. 5.33 x 10'N d. 8.91 x 10'N

please answer 8-13

Answer 1

Radius of spool, R = 2.00cm circumference of spool c=2TR length of thread l = 75m = 7500ch No. of furns of thread on the spool - 2TR 11 7500 2T X2 = 597) [Info]