Outline for “Acceleration of gravity”

A. Experiment title/ date

B. Basic formulas used

C. Measurements and analysis

1.

　

weight(unit)

size or diameter (unit)

Small ball

 　 　

Big ball

 　 　

2.

small ball:

Measured

y, (m)

Five elapsed time(sec)

t average

(sec)

t1

t2

t3

t4

t5
　 　 　 　 　 　 　
　 　 　 　 　 　 　
　 　 　 　 　 　 　
　 　 　 　 　 　 　
　 　 　 　 　 　

　

Plot y- t graph, and modify “t” to get y- t2 graph.

Print out “statistics” for modified data and find out “g”.

Calculate %error:   g(true)= 9.795 m/s2 , σg= standard deviation of slope

           

3. Do above again for big ball.

4. Extra credit: (only if you have time )

　

g (m/sec2)

A/m (m2/kg)

Small ball

 　 　

Big ball

 　 　

Plot “g – A/m” (“A” is the cross section area of the ball and “m” is the mass. )

If you can give a good explanation on the graph, you will get an extra credit.

Hint:    Consider the air resistance and the magnitude of air resistance is proportional to “A/m”.

D. Conclusions

  1. Discuss you results as much as possible.
  2. Answer questions on p.18.

　

Good luck!                                                                                                                  --- Designed by Ben-Li Young