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Lesson 4

1. Lesson 4

1.5. Explore 4

Mathematics 30-3 Module 6

Module 6: Measurement

 

In Try This 3 you may have noticed that it is possible to take accurate measurements without using numbers, although they will have a low degree of precision. By looking at the clear plastic container you can see whether the tank is empty, partially full, or completely full. Therefore, the measure is accurate to this level. However, this measurement will have a low precision because there are no markings.

 

In other situations it is important to have both accurate and precise measurements—estimates are insufficient. In the next Self-Check you will apply accuracy, precision, and uncertainty to specific measurements.

 

Self-Check 2


textbook

Answer “Practise Your New Skills” questions 3, 4, and 7 on pages 105 and 106. Answer

 

 

Try This 4

 

The speed of a vehicle is usually shown on the speedometer. However, many GPS systems and some road signs also display speed.

 

The photo on the left shows a speedometer with both km/h and MPH scales. The middle image shows a sign that reads Speed Limit 25 with a reading of 23 labelled Your Speed. The image on the right shows a GPS with a speed of 92 km/h shown.

speedometer: Dynamic Graphics/liquidlibrary/Thinkstock; speed limit: © Olivier/5826883/Fotolia; GPS: iStockphoto/Thinkstock

 

  1. The speedometer shown measures both kilometres per hour (km/h) and miles per hour (MPH). For which speed are the markings calibrated?
  2. Determine the uncertainty for each scale of the speedometer, the speed on the GPS, and the speed displayed on the speed limit sign.
  3. Which measure do you expect to be the most accurate? Explain.
  4. Which measure has the lowest degree of precision? Explain.
  5. Which measure do you expect to have the lowest tolerance? Explain.

course folder Save your responses in your course folder.

 

Share 3

 

With a partner or in a group, consider your answers to Try This 4 and answer the following questions.

 

Your car displays the speedometer and GPS as shown in the previous images. Now you pass the speed limit sign. The speedometer read 15 MPH, the GPS read 24 km/h, and the speed limit sign read 27 km/h.

  1. If the speed limit is 25 km/h, which instrument displaying the speed will you go by?
  2. Will you change your speed? Explain.

course folder If required, place a summary of your discussion in your course folder.