Answers to practice problems for Test 1

1. weather balloon
   1. volume = 50 cubic meters
   2. total mass = 63 kg
   3. about 2 days, blowing night and day

2. The position of an electron ...
   1. -40.8 m
   2. -23.1 m/s
   3. -4.6 m/s^2
   4. left
   5. 3.71 s

3. Pam tosses apple
   1. 3.67 s after she tosses
   2. 4.57 s after she tosses
   3. 26.8 m/s downwards

4. Tom rolls ball
   1. uncertainty in distance = 5.8 percent
   2. 240 s
   3. min 233 s, max 247 s, or 240 s +/- 7 s, or 240 s +/- 2.9 percent