CHAPTER 2 ANSWERS: College Physics, 7th ed. Sears, Zemansky and Young

 

2 - 1.                a) 15 mi/hr             b)22 ft/s

2 - 2.                3 km

2 – 3.               41 min
2 – 4.               + 6.0 cm/s; -1.5 cm/s

2 – 5.               a) +5 m/s                b. +12 m/s              c. +19 m/s

2 – 6.               a) IV        b) I          c) V         d) II         e) III

2 – 7.               a) 5 m/s; 10 m/s     b) 20 m/s

2 – 8.               0.960 m/s

2 – 9.               a) 0; 1 m/s2 ; 1.5 m/s2 ; 2.5 m/s2 ; 2.5 m/s2 ; 2.5 m/s2 ; 1 m/s2 ; 0

                        b) 2.5 m/s2 ; 0.8 m/s2 ; 0

2 – 10.             a) –1 m/s2               b) –3 m/s2              c) –4 m/s2

2 – 11.             12 m/s2

2 – 12.             a) –1.5 m/s2 (left) b) –1.5 m/s2 (left)                  c) +4 m/s2 (right)

2 – 13.             ?

2 – 14.             a) 1 m/s2                 b) 0; 2 m/s2

2 – 15.             a) 5.13 ft/s2            b) 477 ft

2 – 16.             80 m/s2

2 – 17.             a) 52.7 ft/s2            b) 373 ft/s              c) 1.53 s

2 – 18.             a) 5 m/s  b) 1.67 m/s2

2 – 19.             a) 0;  6.25 m/s2 ; -11.2 m/s2 b) 100m; 230m; 320m

2 – 20.             a) 35.6 ft b) 328 ft

2 – 21.             a) 1.2 x 104 m/s   (12 km/s)   b) 96.4% c) 576 min

2 – 22.             ?

2 – 23.             980 m

2 – 24.             a) 3.83 m/s             b) 0.782 s

2 – 25.             a) 122m                   b) 49 m/s

2 – 26.             a) 22.8 m, 3.1 m/s (up); 16.4 m, 11.6 m/s (down)               b) 3 s      c) 21.4 m/s

2 – 27.             a) 34.6 m/s             b) 49.6 m                c)20.5 m/s

2 – 28.             a) 4.93 s                  b) 36.3 m/s

2 – 29.             a) 56 ft/s                 b) 49 ft                    c) 0          d) 32 ft/s, downward

2 – 30.             a) 2.45s                   b) 4.9 s                   c) 7.35 s                  d) 3.67s

                        e, f and g) 9.8 m/s2, downward

2 – 31.             a) 815 ft/s2             b) 25.5g                  c) 1320 ft                d) No, a = 20.6 g if constant

2 – 32.             a) 3.7m                    b) 88m                    c) 20m

2 – 33.             a) 6 m/s, to the right             b) 13.5 m/s, to the left          c) 12 m/s, to the left

2 – 34.             a) 30 s                     b) 90 s

2 – 35.             Man on shore: 29 min; man in boat: 41.6 min

2 – 36.             0.987 m

2 – 37.             3.6 m/s2

2 – 38.             a) 8 m/s; 17 m/s     b) 16.5 m/s; 36 m/s

2 – 39.             a) 9 m/s; 11 m/s; 13 m/s       b) 1 m/s2                 c) 8 m/s                  d) 8s       e) 8.5 m

2 – 40.             a)                                             b) 0.224 s


 


2 – 41.             5.26 m from point directly below you

2 – 42.             a) yes                     b) passenger train travels 538 m

2 – 43.             a) 180 m                  b) 30 m/s

2 – 44.             a) 137 m/s              b) 122 m

2 – 45.             a) 11.2 s                  b) 38m                    c) Truck; 22.4 m/s; auto; 29.1 m/s

2 – 46.             a) 1.22 m b) 2.46 m/s, downward; 9.8 m/s2, downward

2 – 47.             a) 22.3 m b) 1.22 s

2 – 48.             3.36 s after first marble is dropped

2 – 49.             a) 3.33 m/s2            b) 5 m/s                  c) 3.75m

2 – 50.             a) 8.85 m/s             b) 0.904 s               c) 0.452 s                d) 3 m

2 – 51.             0.47 m

2 – 52.             a) 16 s                     b) 384 m                 c) 28 m/s

2 – 53.             15.7 m

2 – 54.             a(t) = 4 m/s2 + (9 m/s4) t2

2 – 55.             a) 12.3 s; 73.5 m    b) 2.21 m/s             c) ?

                        d) 9.79 m/s             e) no                       f) 4.65 m/s; 25.8 s; 120 m

2 – 56.             a) 327 m

2 – 57.             a) 27                        b) 109

2 – 58.             a) 16 m/s                b) 4.6 m; 10,800 m c) 19.6 m/s

                        d) 9.8 m/s