钟摆的周期 Period of a Pendulum

• E. why do you think Mr. Purcell gave specific instructions about how to use the stopwatch？ • This can be the evidence for why we timed 10 periods during a pendulum experiment rather than only one, if we measure many periods our error does not increase, we can get a more accurate answer by timing 10 periods.
Analysis:
A. Our independent variable was the mass of the bob, we found that there is no relationship between the period and the mass, we can be confident about it because there was no really big change in timing during changing the mass B. we can mention this from the data collection C. the data can not show the strong correlation between the variables.
Controlled variables….
Controlled variable.1
Controlled variable.2 Controlled variable.3
angle of displacement value: 20 degree
length of pendulum value: 50cm
Period of a Pendulum’s formula:
l T 2 g
Thank You!
BY
Katherine and Vicky
L/O/G/O
Period of a Pendulum
L/O/G/O
Hypothes is…..
• If the mass of the bob is increase
then the period will be longer
The period of pendulum will be affected by the mass
We found out the Related factors on the internet . There is a relationship between the period and the length. Acceleration of gravity also affects the period.
distribution value: at the end of the pendulum
Data collection
Trial# T1 Iv 1 14.52 Iv 2 14.05 Iv 3 14.65 Iv 4 14.16 Iv 5 14.45
T2
T3 T4 T5 T Ave +_
14.75
14.58 14.66 14.58 1.5
14.06
13.98 14.07 14.33 1.4
14.52
14.59 14.17 14.39 1.4
14.20
14.13 14.15 14.08 1.4
14源自文库53
14.45 14.52 14.55 1.4
Graph
1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 50 100 150 200 250 300 350
our hypothesis was wrong, we thought that if the mass increase then the period will be longer but real data proved that there is no relationship between the mass and the period.
Every measurement we make has an uncertainty…..
Measurements are never perfect, the more measurements you take of the same parameter, the more accurately you can calculate the value
Variables….
Dependent variable : Period (time) Independent variable : mass of the bob
Controlled variable: angle of displacement, length of pendulum, distribution (these variables will not be changed)
the largest uncertainty is period, because we can’t stop the stopwatch at the exact right time
What’s the uncertainty?
• The imperfection in all measurements is called uncertainty • In the physics we will write an uncertainty almost every time we measure a measurement • (measured value +_ uncertainty) proper units