What is the Effect of Various What is the Effect of Various Road Surfaces in Beijing on the Road Surfaces in Beijing on the

Deceleration of a Bike when the Deceleration of a Bike when the Brakes are Fully Applied? Brakes are Fully Applied?

Description of the ExperimentDescription of the Experiment

Raw DataRaw Data

Surfaces Gravel Road Tile Road Grass Wet Road

1 2 3 1 2 3 1 2 3 1 2 3 1Distance / ± 0.05 m

6.37

6.21 6.03

5.17

5.05 4.98 5.42 5.28 5.33

4.80

4.64

4.69 7.46

Time 1 / ± 0.1 s 7.43

14.40

9.03

5.97

15.20

17.50

6.75 5.93 5.56

4.75

5.03

4.87 9.68

Time 2 / ± 0.1 s 5.93

13.19

7.50

4.50

13.84

16.19

5.13 4.25 3.97

3.44

3.77

3.68 7.76

Velocity / ± 0.5 km/h

25 25 25 25 25 25 25 25 25 25 25 25 25

Analysis of the DataAnalysis of the Data

Surface Gravel

Road Tile Road

Grass Wet Road

Trial 1 3.672 4.829 4.481 4.948 2.913Trial 2 3.803 4.811 4.467 4.922 NATrial 3 4.015 4.841 4.444 4.967 NAAverage 3.830

± 0.170

4.827 ± 0.015

4.464 ± 0.018

4.987 ± 0.023

2.913

Deceleration on Difference Surfaces (From Deceleration on Difference Surfaces (From Graph)Graph)Deceleration on Difference Surfaces (From Deceleration on Difference Surfaces (From Calculation)Calculation)

s = ut + ½ at2

4.98 = (6.94)(17.50 – 16.19) + ½ (a)(17.50 – 16.19)2

4.98 = (6.94)(1.31) + ½ (a)(1.31)2

4.98 = 9.09 + (0.86)(a)(0.86)(a) = -4.11a = -4.78 m/s/s

Velocity vs Time of a Bike (on main road)Velocity vs Time of a Bike (on main road)

Surface Gravel Road Tile Road

Grass Wet Road

Trial 1 3.60 4.66 4.44 5.01 3.19Trial 2 3.87 4.76 4.53 5.18 NATrial 3 3.93 4.78 4.52 5.05 NAAverage 3.80 ±

0.24.730±0.06

4.50 ± 0.04

5.08 ± 0.1

3.19

ConclusionConclusion

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