• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Physics IA -motion

Extracts from this document...



Of A Hot Wheels Radar Gun



Title: The accuracy of a Radar Gun

Aim: To investigate the accuracy of a “hot wheels” radar gun.

Theory: Radar guns are, in their most simple form, radio transmitters and receivers. They send out a radio signal, and then receive the same signal back as it bounces off the objects. However, the radar beam is different when it comes back, and from that difference the radar gun can calculate vehicle speed.The gun uses the Doppler Effect to calculate the speed of the object in the beam's path. Using a comparison of frequency shift between received images instead of the frequency shift between sent and received frequencies creates what is known as moving radar, the radar must be stationary to measure speed.

By utilizing a number of different equations, it is thought that the accuracy of a Hot Wheels Radar Gun will be found. The equations that will be used are as follows:

  • Constant Velocity = distance (m)/time(s)
  • Instantaneous Velocity = small distance (m)/small time (s)
  • Conversion fromm/s to km/h = V × 60² / 1000
  • Uncertainty = limit of reading/2
  • Percentage Uncertainty = (uncertainty/value) × 100.
  • Percentage Deviation =( Exp Value – Accepted Value) / Accepted Value   X  100%


  • Hot wheels radar gun
  • Video recording device (mobile phone)
  • Markers (shoes)
  • Car


  • Chalk  
  • Measuring Tape

Diagram: The set up for the radar gun experiment








  1. A distance of 10m was measured out and marked with chalk.
  2. Three markers were used to mark out the distances of 0m, 5m, and 10m.
  3. The radar guns settings were changed to 1:1 and km/h.
...read more.














Distance Travelled

Velocity on Speedometer (Expected Value)

± 5

R.G. Velocity

± 0.5

Time taken according to V.D. (seconds)    ± 0.005













Table 3:

Calculating and finding uncertainties:

To find the uncertainty of a measurement one must simply find the limit of reading for the instrument being used and half it. The limit of reading is equal to the smallest graduation of the scale of an instrument. E.g. it can be seen above that the “time taken according to V.D.” table has an uncertainty of 0.005 seconds. This is because the smallest graduation in time shown on virtual dub is 0.01 seconds, hence 0.01/2 = 0.005.

Converting into percentage uncertainties:

When viewing the results of percentage accuracy the uncertainty must also be in percentage form. The following formula can be utilized to find this, percentage uncertainty = (uncertainty/value) × 100.

After finding the percentage uncertainty, one is able to find a more accurate uncertainty for the “I.V. km/h"

Finding velocity and Accuracy

To be able to compare the R.G. velocity to the instantaneous velocity one must first know the following components, time and distance. The formula, V= s/t gives you the velocity in m/s; however it then needs to be converted into km/h. This is done by multiplying the value by 60², then dividing by 1000, like so: value in km/h = m/s value × 60² ÷1000.

...read more.



The data that was accumulated shows that the radar gun has an average accuracy of 93.473% ± 1 for velocities that range approx. 20km/h-40km/h. After observing the tables and graphs it can be seen that velocity is inversely proportional to the accuracy of the radar gun, hence the accuracy decreases as the velocity increases. It was also gathered that the gradient of an “accuracy vs I.V.” decreases as the velocity increases, again another inverse relationship. The average accuracy was found to be 6.527% off 100% accuracy, which is a reasonable outcome, depending on the way one looks at it. In summation, this experiment was an overall success as the aim to find the accuracy of a Hot Wheels Radar Gun was met, and much was learned about the components that make up aspects of physics such as constant velocity, instantaneous velocity, etc.


In relation to the possible errors that may have occurred, if this experiment were to be repeated, the following modifications would be made.

  • Measure the velocity of the car with a more accurate device. This would in turn cause the final uncertainty to be smaller and the accuracy higher.
  • A larger space to conduct the experiment. An area such as an airport run way would be ideal for this experiment as it would give ample time for the driver to reach and maintain a constant velocity.
  • More care should be taken in both the recording and calculating process of data to reduce error.
  • Prac should take place in doors, to avoid environmental factors that may contribute to a higher error.
  • Rounding should be kept to a bare minimum in order to accumulate the most accurate data.

        Riki Nagoya                                                           21/04/08                                                            Mr Marshall

...read more.

This student written piece of work is one of many that can be found in our International Baccalaureate Physics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Physics essays

  1. Physics IA bouncing ball

    10 till reaching a meter, and measuring multiple times to get an average, that in this case was measuring 3 times per measure of height the time it took for the ball to stop bouncing completely and then making a average time, that the hypothesis of height being proportional to

  2. Analyzing Uniform Circular Motion

    = 2 F2 = Relative Error F2 = Absolute Error This process was followed to attain the correct uncertainty and the actual value for each of the values represented in the data above. For the following tables, which require the reciprocal of the original independent value, the same method was use (for e.g.

  1. In this extended essay, I will be investigating projectile motion via studying the movement ...

    Secondly, as expected, the projection range of metal ball increases with both increases of compressed spring length and the projection height, satisfying our predictions of such a trend to occur. There are differences between the experimental values of range and the corresponding theoretical values of range.

  2. Experiment on looking at enthalpy of solutions

    15,20 15,15 216,00 15,10 15,20 15,15 217,00 15,10 15,10 15,10 218,00 15,10 15,20 15,15 219,00 15,00 15,20 15,10 220,00 15,00 15,10 15,05 221,00 15,00 15,20 15,10 222,00 15,00 15,20 15,10 223,00 15,10 15,20 15,15 224,00 15,10 15,20 15,15 225,00 15,10 15,10 15,10 226,00 15,10 15,20 15,15 227,00 15,00 15,10 15,05

  1. The purpose of this lab is to examine impact craters. Impact craters occur when ...

    and (natural log of the energy from the crater) is shown below with its graph as well. will be the y-axis, while will act as the x-axis. H will be taken in centimeters, D will be taken in centimeters, g will be taken using , and m will be taken using grams.

  2. Physics IA 0906 Planning

    > Different set, types of spring and spring system but all of them have to connect to one metal block only. For the spring to use in the spring system experiment, make sure they are the same, with same length, same shape, same size.

  1. Nuclaer Physics

    high energy light * After decays and interactions, nuclei may have excess energy, therefore being unstable. This is where they release a ? particle with the excess energy. Often happens with the decay. * E.g. 13153I --> 13154Xe + �- + ?

  2. HL Physics Revision Notes

    Newton?s third law states that when a force acts on a body, an equal and opposite force acts on another body somewhere in the universe. One example would be two roller-skater?s pushing off one-another Additional: Mass is the amount of matter contained in an object measured in kg, whilst weight is a force measured in N.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work