Physics Investigation:

The effect of speed on braking distance

Hashim Al-Hasani 11R

Intro

Speed is the travelled distance for every moment/unit of a set time. Speed, distance and time are all related with each other, shown in the following equation, which can be rearranged to find the formula of each measurement:

Speed (m/s) = Distance (m) ÷ Time(s)

The braking distance of an object is the distance it takes to slow the object down, until it is has stopped (stationary). The object will only become stationary when the driving force is being counter-forced, for example friction and air resistance.

The kinetic energy of an object is the energy it gains due to its motion. The equation for kinetic energy is:

 What factors can affect the braking distance of an object?

Well there are 3 main factors that affect the braking distance of an object:

The height from which the object is released

This can affect the braking distance as the higher the object is when it is released, the greater it’s original GPE. As the object continues downwards, its GPE decreases, and its kinetic energy increases by the same amount of gravitation potential energy lost.

450

50m

Reading

Speed

Distance

m/s

mm

1

0.71633

343

2

0.70225

277

3

0.71023

320

4

0.71225

320

5

0.72254

348

40m

Reading

Speed

Distance

m/s

mm

1

0.72464

325

2

0.74184

280

3

0.74627

331

4

0.73746

293

5

0.75301

319

90m

Reading

Speed

Distance

m/s

mm

1

1.12108

730

2

1.1062

719

3

1.12613

760

4

1.11607

749

5

1.12613

723

80m

Reading

Speed

Distance

m/s

mm

1

1.05485

646

2

1.04167

644

3

1.04167

676

4

1.04603

658

5

1.04167

659

70m

Reading

Speed

Distance

m/s

mm

1

0.94697

564

2

0.95057

570

3

0.9434

569

4

0.94697

581

5

0.95057

581

Height Dropped (cm)

Average Speed (m/s)

Average Distance (mm)

90

0.23

41

80

0.46

134

70

0.61

219

60

0.74

310

50

0.71

322

40

0.83

447

30

0.95

573

20

1.05

657

10

1.12

736

MARBLE RESULTS

Confidence on the Conclusion

On the whole, I am quite confident with my conclusion. I attained a set of results which strongly suggested that speed of the ball had the effect on the ball’s breaking distance. Although, as most of the graphs show, many of the range bars are a bit large, meaning that the results are not very reliable as there is a large scatter of data, perhaps this was because of the ramp bent as the ball rolled on or that the light gate wasn’t positioned correctly at that time, justifying the reason why its results was so scattered.

Throughout the experiment, I had obtained many outliers in my results, as shown by the 2 Tables. These may have occurred because of any of the following reasons:

• On some repeats, the position of the light gate wasn’t in the same place as other repeats or therefore making

Despite these outliers, the majority of the averages were close to or on the curve of best fit, so after eliminating outliers, the results were reliable on the whole.