You work out the refraction index from angle readings that each wobble a little. What happens to that wobble?

• It moves through the formula into the calculated index
• It stays behind in the angles
• It cancels itself out in the math

You add two measured lengths. How do you combine their uncertainties?

• Add their percentage wobbles
• Add their absolute ranges
• Multiply their absolute ranges

One reading is 10.24 and another is 10.11. What is their difference?

Answer: ______________

Each input wobbles by about 0.01, yet 10.24 minus 10.11 carries a huge percentage wobble. Why?

• The answer 0.13 is tiny next to the wobble of the inputs
• The inputs were rounded to too few digits
• Subtraction always doubles every input wobble

A value wobbles by 2 percent and you square it. About what wobble does the square carry?

• About 1 percent
• About 2 percent
• About 4 percent

A length measured to three digits lets you quote a result calculated from it to ten digits.

Circle one:   True   False

A student adds two masses and combines their percentage wobbles. What is the mistake?

• The units of mass forbid adding the two values
• Averaging the masses would remove all wobble
• A sum needs absolute ranges, not percentage wobbles

Your angles wobble by two degrees and your distances are nearly exact. You want a tighter refraction index. What do you improve first?

• The distances, because exact numbers are suspicious
• The angle readings, because their wobble moves the answer most
• Both equally, because every input matters the same