number 
answer 
1 
(a) 8.9 m/s (b) 1.19 s (c) 0.33 s 
2 
6.6 s 
3 
(a) 2.3 m/s^{2} [up] (b) 2.4 N tension (c) 21 N upward on top string 
4 
41 cm 
5 
(a) student has larger momentum (b) student also has larger kinetic energy (c) bullet more dangerous due to small surface area 
6 
12 m/s 
7 
0.76 s 
8 
0.19 m/s 
9 

10 
0.00108 T 
11 
4.5 cm 
12 
4.0 m 
13 
9.95 ^{o} 
14 
more than enough to get to sea level (4.21 x 10 ^{3}m^{ } 
15 
0.468 MeV 
16 
not possible since kinetic energy larger after than before 
17 
0.42 m/s 
18 
3.2 x 10^{7} m/s 
19 
5.4 x 10^{6} V 