which metric unit and prefix would be the most convenient to measure the following?

Question

which metric unit and prefix would be the most convenient to measure each of the following?
a.the diameter of a giant sequoia tree
b.the diameter of a human hair
c.time necessary to blink your eye
d.mass of gasoline in a gallon
e.mass of cold virus
f.amount of aspirin in a tablet
g.mass of concrete to pave a parking lot



thanks guys i owe you and if you could explain

Answer 1

a. meters
b. micrometers
c. nanoseconds
d. kilograms (volume in liters)
e. milligrams
f. micrograms
g. cubic meters

Read this article to understand more: http://en.wikipedia.org/wiki/SI_Units

Think about what you are measuring in each case:
a. & b. diameter is a distance measurement
c. time is measured in seconds minutes and hours no matter what system of measurements you use. The SI notation would be the prefix for the size of that unit.
d. & e. Mass is a maeasurement of weight.
f. is a measure of weight as well
g. is a measure of volume that relates to size. You could measure how much concrete you need in liters, but that won't tell you how much area that concrete will cover that's why cubic units would have to be used.

Answer 2

Normally we just measure things in the standard SI units, with no prefixes (meters, seconds, newtons, etc). Prefixes can muddy the water sometimes, especially when you forget to convert. But someone wants you to learn them, so he we go.

Here they want you to use something on the magnitude of the thing you are measuring, so you don't have to say 1000 milligrams when you can say 1 gram.

A. Meters. The trees are big and diameter would be best measures in meters, ans opposed to something smallest like centimeters.

b. Microns, or 1 x 10^-6 meters. Same reason. They want yo to use units here on the same magnitude as the thing you are measuring. 10 microns may be easier to understand than 10^-6 meters; at least that is the reasoning.

c. seconds. Will probably take 0.1 second, so seconds is fine. You could also use ms or milliseconds. The time would be 100 milliseconds.

d. kilograms. there is around 6 pounds to a gallon, so around 14 kilograms.

e. mass of a cold virus. I would use nanograms, or 1 x 10^-9 g.

f. amount of aspirin in a table. Measured in milligrams.

g. mass of concrete to pave a parking lot. Metric tons, or 1000 kilograms.

Most physicists and chemists are comfortable using 1 x 10^-34 or other strangely sized units without any difficulties, especially if it saves us from making a dumb mistake in converting back and forth. But when you can, keep things on the same magnitude as the thing you are measuring. Why say 3600 seconds when you can say 1 hour? It has more meaning sometimes.

Answer 3

a. meters
b. millimeters
c. milliseconds
d. grams
e. micrograms, or possibly nanograms (i am not a biologist)
f. milligrams (just look on the bottle)
g. kilograms

meter is the standard unit of distance
second is stantard unit of time
kilogram is standard unit of mass

All you have to do is choose the proper prefix, which is basically used for allowing to work with a more convenient number.
For example if the tree trunk is 10 meters in diameter, it is much easier to work with the number 10, rather that trying to work in millimeters, and having to work with the number 10,000mm.

Hope that helps.

Answer 4

a. meter

b. milimeters (x 10^-3 m)

c. miliseconds (x 10^-3 s)

d. kg / gallon

e. micrograms (x 10^-6 g)

f. miligrams (x 10^-3 g)

g. kilograms (x 10^3 grams)

I'm not quite sure what you meant by prefixes, but I gave you the scientific notation equivalent if that's what you're looking for...

Answer 5

Metric time only works on April 1st.

Answer 6

a: meter
b: micrometer
c: nanosecond
d: grams or kilograms
e: nanogram
f: miligram
g: kilogram or metric ton

Answer 7

that's a tricky question..

Answer 8

515km to dm