Ticker Timer Answers

 

Grading Rubric                                Lab should be in this order:

25 Neatness                                        1.  Pre-Lab

30 Pre-lab questions                           2.  Graphical Analysis for #7a and b from Pre-lab

15 Graphical Analysis                          3.  Graphical Analysis for lab data

30 Post-lab questions                          4.  Post Lab Questions

 

Pre-Lab

1a.  Dots are widely spaced

2a.  Dots are close together

3a.  1/60 = 0.0167 seconds between each tap

4a.  T = 1/f or f = 1/T

5 points 5a-i

5a.  Constant speed.  Dots are evenly spaced.

b.  1/60

c.  2/60 or 1/30

d.  3/60 or 1/20

e.  4/60 or 1/15

f.  1/60

g.  1/60

h.  1/60

i.  1/60

5 points 5 j-m

j.  119.76 or 120 cm/s

k.  120 cm/s

l.  120 cm/s

m.  120 cm/s

5 points 6 a-e

6a.  No, the dots are not evenly spaced.  It appears to be speeding up.

b.  60

c.  120

d.  180

e.  240

5 points 6 f-i

f.  120

g.  240

h.  360

i.  480

5 points 6 j-m

j.  7200 cm/s

k.  7200 cm/s

l.  7200 cm/s

m.  7200 cm/s

 

 

Graphical Analysis for Question 7a and 7b for pre-lab (5 points for this section)

Notes:

For Distance vs. Time Graph

Slope at first point = 179.64

Slope at second point = 239.52

Slope at 3rd point = 359.281

Slope at 4th point = 419.162

 

For Instantaneous speed vs. time Graph

Slope is constant at 7185.6

Graphical Analysis for Real Data (example given here is data taken by Mr. Young)

(15 points for this section)

 

Post-Lab Questions (3 points each – 30 points total possible this section)

1.  The tape at dot 0 is moving at 0 cm/sec.  By dot 1, the tape has sped up to its instantaneous velocity.  The distance traveled is then equal to the initial velocity and the final velocity divided by 2.

2.  a = 2d/t2

3.  d = 1/2 at2

4.  Answers around 500 – 900 cm/s2 are accepted

5.  Answers around 5.00 to 9.00 m/s2 are accepted

6.  Objects fall to Earth at a rate of 9.8 m/s2

7.  After 2 feet, it has hardly accelerated

8.  No.  Air resistance will begin to slow it down

9.  True

10.  False