# Measuring The Acceleration Of Free Fall

**Topics:**General relativity, Measurement, Linear equation

**Pages:**2 (270 words)

**Published:**February 3, 2015

•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

Please join StudyMode to read the full document