Lesson 3

1. Lesson 3

1.3. Explore 2

Mathematics 30-3 Module 6

Module 6: Measurement

In Try This 2 you should have determined the tolerance by calculating the difference between the maximum and minimum acceptable dimensions of the object you were measuring. You also learned several different ways you can express this tolerance. You will now apply this knowledge by writing the specifications for a design.

Self-Check 1

Turn to page 93 of the textbook, and complete “Example 1.” Check your work with the solution that follows on pages 93 and 94.

In Self-Check 1 you practised finding the nominal value and the maximum and minimum values. The difference between the maximum and minimum values is the tolerance. In the next Try This you will apply this knowledge to plumbing in a home. Sometimes when you are not working from blueprints, you have to make some assumptions about what the maximum and minimum values would be.

Try This 3

This is an illustration of five drainpipes. Two of the drainpipes have acceptable slopes, and three of them have rejected slopes.

Hania is renovating her basement and has just finished running drainpipes for the sink, toilet, and shower. She has a plumbing inspector check her work. After taking some measurements, he tells Hania that the slopes for some of her drains are not correct. He explains that horizontal drain lines need to be steep enough for material to move. However, if they are too steep, the liquids move faster than the solids and the drain may clog. The illustration shows a list of angles that he checked.

Estimate the maximum allowable drain angle for a horizontal drain. What assumptions did you need to make in finding your estimate?
Estimate the minimum allowable drain angle for a horizontal drain. What assumptions did you need to make in finding your estimate?
Express this tolerance using the following four notations, which were discussed earlier:
- nominal value (tolerance)

Save your responses in your course folder.