Density Review

• Science
• Secondary Education

Density Review

• Unit conversion
• Significant figure
• Density review + density in liquid 
• Calculation practice 

Unit Conversion

• simple
• compound 

Snowdon is the highest mountain in Wales
It is 1085 m high. What is it in cm?

1. 10850
2. 108.5
3. 108500
4. 10.85

Conversion Factor

Conversion Factor

Conversion Factor

Conversion Factor

Changing Density - 9kg/m to g/cm

Changing Density - 9kg/m to g/cm

Step 1: 

Convert 9 Kg to grams

Changing Density - 9kg/m to g/cm

Step 2: 

Convert m to Cm

Changing Density - 9kg/m to g/cm

Step 2: 

Convert M to Cm

1 Meter = 100 cm

Changing Density - 9kg/m to g/cm

Step 3: Simplify

9000/100

You can write your answers here

Significant figure

What is significant number

Significant figures are each of the digits in a number that are used to express it, to the required degree of accuracy, starting from the first non-zero digit. The first significant figure, or significant digit, of a number is the most important digit because it expresses the size of the number.

What is significant number

To locate a significant figure, you need to find the first non-zero digit. This is the first significant figure. The next digit is the second significant figure and so on.

 

A significant figure could be to the left of the decimal point or the right of the decimal point.

What is significant number

There are significant figure rules that will help you identify all the significant figures in a given number:

•  Non-zero digits are always significant.
• Any zeros located between non-zero digits are significant.
• Trailing zeros are only significant if a decimal point is present.

Example

What is the significant figure of 0.037?

The first non-zero digit is the 3 in the hundredths place.

0 in front of round number in decimal is insignificant

There is a decimal in this number, but no trailing zeros.

0.037 has 2 significant numbers

Write down the first digit of the significant figure of 0.0943

Write down the number significant figure of 689

Write down the number significant figure of 4.450

Round 0.4275 to 3 significant figure

Density review

Liquid of different density

What would happen if
Mercury density = 13,600 kg/m3
Lead density = 11,340 kg/m3

3 g/ml

5 g/ml

6 g/ml

10 g/ml

Density Calculations

Additional Practice - See google slides

A student pours out 1 litre of a liquid and finds its mass is 0.7 kg. Calculate the
density of the liquid in g/cm3.

A block of wood has a density of 0.8 g/cm3. The block measures 30 cm x 10 cm x 10 cm. Calculate the mass of the block of wood in kg.