2/3/10

Post date: Feb 03, 2010 6:27:22 PM

Bell Ringer: A ball is launched upward at 31.8 m/sec. If its acceleration is -9.901 m/s/s, how high does it get before it begins to fall? (hint: What is the ball's velocity the instant before it begins to fall?)

• • Finish chapter 4 notes

• Do page 77: 25, 26 (due tomorrow)

  • For review (not to be turned in):

    • Finish last year's Mario practice test

    • Page 82: 1, 2, 5, 10, 12, 14, 16-18

Answers for Mario practice test:

1. Given: vi = 0, vf = 45 miles/hour, t = 4 seconds, Answer: a=5m/s/s

2. Graph with distance on the y-axis, time on the x-axis. Graph begins at the origin (0), and has a curve upward (a parabola) for the first 4 seconds. At 4 seconds the curve becomes a straight line moving up and to the right for the next 10 seconds.

3. Given: vi = 3.55 m/sec, t = 0.388 seconds, a = -9.80m/s/s, Answer: vf = -0.252 m/s

4. Given: vi = 28 m/sec, vf = 0, d = 65 ft, Answer: a = -2.0 x 10^1 m/s/s

5. Given: d = 18.5 ft, vf = 0, a = -9.80 m/s/s, Answer: vi = 10.5 m/sec

6. Given: vi = 0, a = -9.80 m/s/s, t = 38 seconds, Answer: d = -7100 m (has fallen 7100 meters)

7. Given: vi = 0, d = 6,378,100 m, a = -9.80 m/s/s, Answer: t = 1140 seconds

8. Given: vi = 0, vf = -9.00 x 10^2 m/s, a = -9.80 m/s/s, Answer: d = -41,300 m (clouds were 41,300 m high)

9. Given: a = 1.5 m/s/s, t = 3.5 sec, d = 21 m, Answer: vi = 3.4 m/sec

10. Given: vi=0, a = -9.80 m/s/s, t = 1.35 sec, Answer: d = -8.93 m (bridges was 8.93 meters above lava)

Answers for textbook review:

1. 8.0 m/s/s

2. a. 247 m/s/s

b. -207 m/s/s

5. 33 m/s

10. 9.2 x 10^2 m

12. a. 43 m

b. 43 m

14. 1.2 sec

16. 71 m/s

17. a. 1.4 x 10^2 m

b. 5.5 x 10^2 m

18. a. 24 sec

b. 7.4 x 10^2 m