Describe
how to determine density using direct measurements of mass and volume.

**Density of a regular solid**

- Measure the mass using a balance
- Measure the width, length and height using a ruler
- Calculate volume (V = w x l x h)
- Calculate density (ρ = m/V)

**Density of a liquid**

- Measure mass of empty measuring cylinder using a balance
- Measure mass of liquid and measuring cylinder
- Subtract 1. from 2. to calculate the mass of the liquid
- Measure volume of liquid (using measuring cylinder)
- NB: measure to the bottom of the meniscus
- Calculate density (ρ = m/V)

**Results:**Oil

- m = 15.74g
- V
= 18.00cm
^{3} - ρ
= 15.74/18 = 0.87g/cm
^{3}

**Density of an irregular solid**

- Measure mass using balance
- Measure volume using the ‘displacement’ method
- (submerge solid in ‘Eureka can’ and measure overflow)
- Calculate density (ρ = m/V)

**Results:**Stone

- m = 146g
- V
= 42cm
^{3} - ρ
= 146/42 = 3.5g/cm
^{3}

Results: Stone

ReplyDeletem= 146g

V= 42cm3

ρ= 146/42 = 3.48g/cm3

Your measurements are to 3 s.f. and 2 s.f. so you must give your answer to just 2 s.f. as we discussed in class.