Return to Physics Index10^{Huh}?

Coleman, Roy Morgan Park High School

RetiredObjectives:To give students some practice at makingreasonableestimates.Apparatus Needed:A good imagination.Recommended Strategy:Listed below are a series of questions which probably cannot be easily answered directly but where an answer to the nearest power of ten can, with some 'educated' guesses, be arrived at. (By nearest order of

magnitude (power of ten), is the answer closer to 10^{1}(=10), 10^{2}(=100),

10^{3}(=1000), 10^{4}(=10000), etc.) In each of the following questions,

parts in square brackets [] represent something that should be

replaced with a specific part or object peculiar to your school.

It is good practice to have the students explain how they arrived at

their answers since there can be some very creative ways of

interpreting the questions.

Example: Question - To the nearest order of magnitude (power of ten),

how many times does a car tire go around while driving to Florida?

Answer (or how to get close) -

Estimates actual

distance (miles) 1500 about 1200 to the center of the state

feet per mile 5000 5280

feet for 1 tire

rotation 10 about 10 depending on car (3.14 X 2.7)

------- -------

750,000 630,000

(rounded to 1,000,000 or 10^{6})

To the nearest order of magnitude, how many:

1) total times does a toilet paper roll go around while the

paper is being removed?

2) blades of grass are there in [pick some bounded area they can see

from the window]?

3) floor tile are there in the building you are currently in?

4) telephones are there in the city of Chicago?

5) teeth are there in the school building on the average school day?

(creative students may include comb, zipper and/or gear teeth)

6) light bulbs are there in the school? (are fluorescent tubes bulbs?)

7) automobile tires are there in Chicago on the average week day?

8) street lights are there in Chicago?

9) leaves on the average tree? (ask in spring or early fall)

10) molecules in the average human body?

11) seconds does the average American live?

12) letters are there in your text book? (creative students may

answer 1 - 26 to the nearest power of ten i.e. 10^{1}. 26 is WRONG

since it is either not a power of ten or there are more letters

than in the entire library - 10^{26}!)

13) books are there in the school library?

14) steps does the average student take while moving around in the

school on the average school day?

15) hairs on the average house cat? (or dog or human head)

16) millimeters high is the school?

17) snow flakes are covering the [pick an area they can see from the

window]?

18) black ants does it take to fill a bath tub? (careful about asking

this question verbally since creative black students may answer 0

(i.e. 1) thinking you mean aunt instead of ant!)

19) stair steps to the moon?

20) sheets of paper are used in the school during the average school

year?

21) ping-pong balls does it take to fill the classroom? (basketballs,

human heads, etc.)

22) ice cubes could you make if you froze lake Michigan?

23) grooves are there on a 33.3 rpm record that plays for 20 minutes on

each side? (10^{0}=1 - there are really 2, one on each side but to the

nearest power of ten, the answer must be 10^{0}(or 1))

24) gallons of water fall on Chicago in an average thunderstorm?

25) keys are there in the school on the average school day? (including

keys on calculators?)

26) grams is the mass of the most popular American made car? (accept 6

but the most correct answer is 1 because the most popular cars are

made by Matchbox or Wheels!)

A real zinger for creative students - To the nearest order of magnitude,

how many times has the Sun gone nova in the last 10^{7}years? If they

answer 0, 10^{0}=1 that means they are answering that it did it once.

They really should answer negative infinity since the only way to get

zero is to have 10^{-infinity}.)