Value of g

1. Featuring the PENDULUM
Gravity Lab Presentation by
David Bang
Jessamyn Hung
Mandy Lin
Jennifer Yoon
SWINGING
WITH
GRAVITY

2. NEWTON’S LAW OF GRAVITY

3. Determine the value of gravity
(g) as accurately as possible.
OBJECTIVE

4. Why did we choose to use the
pendulum?
How does the pendulum relate to
gravity?
PROCEDURE:REASONING

5. Is it possible to measure gravity
using a pendulum?
HYPOTHESIS
If gravity puts force downwards on the pendulum,
we should be able to calculate gravity using the
time of one period.

6. STEP ONE: CREATING MODEL
PROCEDURE: TRIAL & ERROR
What were the errors
for our first trial?
How did we improve?
Left:
Trial 1
Right:
Final Trial

8. PROCEDURE:EXPERIMENT
What tools and equipment
did we use?
Which applications and
programs helped our process?

9. STEP TWO:EXPERIMENT
PROCEDURE:EXPERIMENT

10. STEP TWO:EXPERIMENTRESULTS:RECORDED DATA
Did having multiple trials help make more accurate
results?

11. Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 10 7.9 .79 .6241
2 10 8.0 .8 .64
3 10 8.0 .8 .64
4 10 7.9 .79 .6241
Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 5 6.4 .64 .4096
2 5 6.5 .65 .4225
3 5 6.3 .63 .3969
4 5 6.3 .63 .3969

12. Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 30 11.5 1.15 1.3225
2 30 11.2 1.12 1.2544
3 30 11.4 1.14 1.2996
4 30 11.0 1.10 1.21
Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 20 9.7 .97 .9409
2 20 9.6 .96 .9216
3 20 9.8 .98 .9604
4 20 9.8 .98 .9604

13. Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 50 15.7 1.57 2.4649
2 50 15.1 1.51 2.2801
3 50 15.3 1.53 2.3409
4 50 15.9 1.59 2.5281
Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 40 13.3 1.33 1.7689
2 40 13.5 1.35 1.8225
3 40 13.1 1.31 1.7161
4 40 13.5 1.35 1.8225

14. Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 70 17.8 1.78 3.1684
2 70 17.7 1.77 3.1329
3 70 17.5 1.75 3.0625
4 70 17.7 1.77 3.1329
Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 60 16.2 1.62 2.6244
2 60 16.1 1.61 2.5921
3 60 16.3 1.63 2.6569
4 60 16.5 1.65 2.7225

15. Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 90 19.7 1.97 3.8809
2 90 19.3 1.93 3.7249
3 90 19.2 1.92 3.6864
4 90 19.3 1.93 3.7249
Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 80 18.7 1.87 3.4969
2 80 18.4 1.84 3.3856
3 80 18.3 1.83 3.3489
4 80 18.2 1.82 3.3124

16. Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 110 21.5 2.15 4.6225
2 110 21.5 2.15 4.6225
3 110 21.8 2.18 4.7524
4 110 21.9 2.19 4.7961
Trial Length (cm) Time (sec) for
10 swings
Period (T) T2
1 100 20.4 2.04 4.161
2 100 20.2 2.02 4.080
3 100 20.3 2.03 4.1209
4 100 20.4 2.04 4.161

18. STEP TWO:EXPERIMENTRESULTS:RECORDED DATA
Finding out the value of “g”:
4𝜋2
𝑆𝑙𝑜𝑝𝑒
Formula:
4𝜋2
4.04𝑚/𝑠𝑒𝑐2
=
= 9.771885546𝑚/𝑠𝑒𝑐2
Where did the formula come from?
9.77 𝑚/𝑠𝑒𝑐2

19. What were the factors that affected the
accuracy of our experiment?
ASSUMPTION & LIMITATIONS
What were our thoughts throughout the
process?

20. Our hypothesis was correct! Using the time of one
period, we were able to calculate a measurement of
gravity. Our final result for gravity was
CONCLUSION
9.77 𝑚/𝑠𝑒𝑐2