Converting
Converting
Log Scale Graphs
Order of Magnitude
100

Given that 

log(x)=2

Find the value of x

x=100

100

Given that 

log(x) = 4.5

Find the value of x, correct to 2 decimal places

x=31622.78

100

The histogram below shows the distribution of brain weights (in grams) of 27 animal species plotted on a log scale.


The brain weight of a mouse is 0.4g. What value would be plotted on the log scale (round to 1 decimal place)

log(0.4)=-0.39794

-0.4

100

Determine the order of magnitude of 4500

log(4500) = 3.653

Order of magnitude is 3

200

The brightness of a star (B) is measured using a logarithmic scale. The logarithmic brightness of a star is recorded as 3.25

Given that:

log(B)=3.25

Determine the actual brightness, correct to 2 decimal places.

B=10^3.25

B=1778.28

200

The distance between two planets is recorded as 100,000km.


Calculate the logarithmic value of this distance.

log(100,000)=5

5

200

The histogram below shows the distribution of brain weights (in grams) of 27 animal species plotted on a log scale.

The brain weight of an African elepaht is 5712g. What is the log of this brain weight (to two significant figures)?

log(5712) = 3.756788

3.8

200

The distance between two cities is 

3.85*10^6

Determine the order of magnitude of this distance.

Order of magnitude is 6

300

The population of a particular insect species is represented by a logarithmic value of 4.

Determine the actual population

log(P)=4

P=10^4

P=10000

300

A microscopc organism has a length of 0.0000356 metres.

Calculate the logarithmic value of its length, round to 3 decimal places.

log(0.0000356)=-4.44855

-4.449

300

The histogram below shows the distribution of brain weights (in grams) of 27 animal species plotted on a log scale.

What brain weight (in grams) is represented by the number 2 on the log scale?

10^2 = 100

100 grams

300

Determine the order of magnitude of 0.00072

log(0.00072)=-3.14

Order of magnitude is -3

400

The intensity of an earthquake is measured using a logarithmic scale. An earthquake has an actual amplitude ratio of 850,000.

Calculate the logarithmic value of the amplitude ratio, to 3 significant figures

log(850,000)=5.929418

5.93

400

The intensity of an earthquake is measured using a logarithmic scale. An earthquake has an logarithmic amplitude ratio of 7.2

Calculate the actual value of the amplitude ratio, to 3 significant figures.

10^7.2=15848931.9246

15,800,000

400

The histogram below shows the distribution of brain weights (in grams) of 27 animal species plotted on a log scale.

Use the histogram, to determine the number of these animals with brain weights of 1000grams or more.

log(1000) = 3

3 or more = 5 animals

400

The mass of a large aircraft is approximately 

2.75*10^5

The mass of a submarine is approximately 

3.2*10^3

Which object is heavier? Justify with calculations.

Order of magnitude of aircraft is 5, whilst order of magnitude of submarine is 3.

Therefore the aircraft is approximately 2 order of magnitudes heavier (aka. 100 times heavier!)


OR calculate actual values: 275,000kg > 3,200 kg. Therefore aircraft is heavier.

500

The intensity of a sound is measured using a logarithmic scale. A particular sound has a logarithmic intensity value of 5.85.

Given that:

log(I)=5.85

Determine the actual sound intensity, correct to 3 significant figures in scientific notation.

I=10^5.85

707945.7843

708000 (3sf)

I=7.08*10^5

500

The concentration of a chemical in a water sample is recorded using a logarithmic scale. It's logarithmic concentration is measured as -4.68

Determine the actual concentration, rounding to 3 significant figures and in scientific notation.

log(C)=-4.68

C=10^-4.68

0.000020892961

0.0000209 (3 sf)

2.09*10^-5

500

The histogram below shows the distribution of brain weights (in grams) of 27 animal species plotted on a log scale.

Use the histogram to calculate the percentage of animals that weigh from 1 gram to less than 100 grams, rounded to the nearest whole percentage.

log(1)=0

log(100)=2

Between 0 and 2 = 4 + 8 

12 animals

12 out of 27 = 12/27 *100

44%

500

The diameter of grain of sand is approximately 

7.5*10^-4

The diameter of a humain hair is

2.8*10^-4

Which object has a larger diameter. Justify your response.

Since they have the same order of magnitude, just compare the numbers.

Since 7.5>2.8, therefore the sand has a larger diameter