42
Units of Scientific Measurements
4.0 mm. Calculate the percentage error in the volume delivered, assuming a
plane (not curved) meniscus.
52. To what temperature must a bath be heated so that a Fahrenheit thermometer
will have a reading that is three times as large as that on a Celsius
thermometer?
53. According to Newton's law, the force exerted by an object is equal to its mass
times its acceleration. The unit of force needed to accelerate a mass of 1 g by 1
cm/sec
2 is called a dyne. What are the units of a dyne in the cgs system?
54. A budding young chemist decided to throw tradition overboard and include
time in the metric system. To do this she kept the unit "day" to refer to the
usual 24 hr time interval we know. She then subdivided the day into centidays,
millidays, and microdays. Solve the following problems, (a) A 100 yd dash
done in 9.7 sec took how many microdays? (b) A 50 min class period lasts for
how many centidays? (c) A car going 60 mph goes how many miles per
centiday? (d) What is the velocity of light in miles per milliday if it is 186,000
mi/sec? (e) What is the acceleration of gravity in centimeters per microday
2 if
it is 980 cm/sec
2 ?