38
Units of Scientific Measurements
Using the Celsius-to-Kelvin formula, we have
K = °C + 273.2 = 46.1 + 273.2 = 319.3
Thus,
H5°F = 46.1°C = 319.3 K
PROBLEM:
Convert 30°C to the Fahrenheit scale.
SOLUTION:
Rearrange the conversion formula to give °F on the left:
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— C = F — 32
°F = -°C + 32
Now we can substitute 30 for °C and solve for °F:
°F =
9 X 30 + 32 = 86.0
Thus, 30°C = 86°F.
PROBLEMS A
When you work these problems, show the units in each step of the calculation, and
show the units of the answers.
1. A brass bar is 2 x 3 x 6 cm. Find its area and volume.
2. A cylindrical rod is 2 cm in diameter and 12 inches long. Find its area and
volume.
3. First-class postage is A cents for each ounce or fraction thereof. How much
postage is required for a letter weighing 98 g? Give your answer in terms of A.
4. What is the weight, in pounds, of 20 kg of iron?
5. The distance from Paris to Rouen is 123 km. How many miles is this?
6. The regulation basketball may have a maximum circumference of 29i inches.
What is its diameter in centimeters?
7. The longest and shortest visible waves of the spectrum have wavelengths of
0.000067 cm and 0.000037 cm. Convert these values to (a) angstroms, and (b)
nanometers.