(Lessons 1-48 7. A block of lead has a weight of 24.500 newtons and a volume of 0.221 cubic meter. The density of the lead block is most nearly (a) 5970 kg/m (b) 11.300 kg/m (c) 21.500 kg/m (d) P11.000 kg/m3 8. A 25-newton force is applied to a wrench, as shown. The magnitude of the torque that this force produces equals 25 N (a) 1.5 Nom 30 ( b ) 3.0 N.m 150 N.m 12 cm- (d) 300 N.m 9. The graph is a plot of the velocity versus time for an object moving in a straight line. The \\ position of the object at 1 = 0 seconds is 0 meters. At what time after 1 = 0 seconds 20 does the object again pass through its initial position? meters per second 10 - (a second 1 2 3 (b) Between 1 and 2 seconds -10 c) 2 seconds -20 - (d) 3 seconds Velocity Time in seconds 10. A pump lifted 50.0 kilograms of water at a constant velocity a vertical distance of 10.0 meters in 75.0 seconds. The average power consumption of the pump is (a) 6.67 W (b) 16.7 W Max 10 (c) 32.7 W (dj ) 65.4 W 11. A rope pulls a 5.2-kg block upward with a constant acceleration of 5.0 meters per second squared. The tension in the rope is (a) 26 N (b) 51 N (C) 63 N T - 5, 219 / 9.814 ) = 5 x ( 5.0 mc ) 12. The efficiency of the first machine is 80.0 percent and the efficiency of the second machine is 50.0 percent. The amount of work done by the second machine is (2) 182 J 455 x 18 - 36 (b) 328 ] 455. J MZ-IONS Work Mz-IOP3 (C) 364 ) 164x 1 5 = 680 out (d): 455 J #1 #2 Physics by Saxon Copyright @ 1993 by Saxon Publishers, Inc. Reproduction for resale prohibited. 60