# Measuring The Acceleration Of Free Fall

Topics: General relativity, Measurement, Linear equation Pages: 2 (270 words) Published: February 3, 2015
﻿Measuring the Acceleration of Free Fall
•Aim: To test the validity of the equation of motion and obtain a value for g

•Equipment: A ball, ruler, a stopwatch

•Principle: sf = si + ui*t + ½at2

•Process:
1. Time how long the ball takes to fall from a maximum possible height. Record your result. 2. Repeat the measurement multiple times in order to obtain a more accurate result. 3. Repeat the experiment for several different heights spread evenly throughout a range of heights.

Time/s
Height/m
T1
T2
T3
T4
T5
Average T
0.6±0.05
0.39
0.35
0.41
0.34
0.36
0.37±0.04
0.8±0.05
0.42
0.44
0.42
0.41
0.39
0.42±0.03
1.0±0.05
0.43
0.49
0.49
0.43
0.47
0.46±0.03
1.2±0.05
0.48
0.50
0.48
0.52
0.50
0.50±0.02
1.5±0.05
0.59
0.53
0.60
0.54
0.57
0.57±0.04

2H
T2
1.2±0.1
0.14±0.03
1.6±0.1
0.18±0.03
2.0±0.1
0.21±0.03
2.4±0.1
0.25±0.02
3.0±0.1
0.32±0.04

•Analysis
Independent variable: Height
Dependant variable: Time taken to fall
Control variables: Shape, size, mass and material of the ball. The initial speed of the ball si =o, ui =0, so h= 1/2gt2
The graph of 2H and t2 is a straight line, and the slope of the line is the value for g.

•Conclusion
g=9.32m/s2

•Error analysis
1. The air resistance works.
2. The reaction needs time.

Distance(m)
±0.005
Time (s)±0.01

1
2
3
4
5
0.6600

Distance(m)
±0.005
Average time (s)
Value of gravity

0.5000
0.44±0.07

1.0000

1.5000

2.0000

2.5000

Average g

Average time
T=(t1+t2+...)/n

gravity
A=2x/t2