Question

Suppose a new tire has a tread depth of 11.2 mm. As the tire begins to wear from use, the depth of each tread decreases. Legally, tires must have a minimum tread of 1.6 mm. However, most tire experts suggest changing the tires before the tread reaches 3.2 mm.

a. The tire treads were measured to have a depth of 7 mm using a ruler with a precision of 1 mm. Determine the amount of tread that has worn off, including the uncertainty.

Answer 1

[AI-generated answer — Bot GPT 3.5]

The amount of tread that has worn off can be calculated by subtracting the current tread depth from the original tread depth:

Original tread depth = 11.2 mm
Current tread depth = 7 mm

Amount of tread worn off = 11.2 mm - 7 mm = 4.2 mm

Since the precision of the ruler used is 1 mm, the uncertainty in the measurement is ±0.5 mm. Therefore, the amount of tread that has worn off, including the uncertainty, is 4.2 mm ± 0.5 mm.