1. EDEXCEL IGCSE PHYSICS 5-1 Density and Pressure Edexcel IGCSE Physics pages 162 to 168 December 4 th 2010 All content applies for Triple & Double Science THIS POWERPOINT IS NOT DUE FOR COMPLETION UNTIL JULY 2012

2. Edexcel IGCSE Specification Section 5: Solids, liquids and gases b) Density and pressure recall and use the relationship: density = mass / volume ρ = m / V describe how to determine density using direct measurements of mass and volume recall and use the relationship: pressure = force / area p = F / A understand that the pressure at a point in a gas or liquid which is at rest acts equally in all directions recall and use the relationship: pressure difference = height × density × g p = h × ρ × g

4. Density (ρ) density = mass volume ρ = m / V unit = kg m -3 Note: 1 g cm -3 is the same as 1000 kg m -3

5. Density examples density / kg m -3 density / kg m -3 Interstellar medium iron hydrogenlead heliummercury airuranium wood (average) gold lithium waterSun’s core plastics neutron star aluminiumblack hole 0.0989 0.179 1.29 0.534 19 100 850 to 1400 10 -25 to 10 -15 13 500 150 000 700 1000 2 700 7 900 11 300 22 610 19 300 10 17 > 4 x 10 17 osmium

6. Question Calculate the weight of a gold ingot of dimensions (20 x 10 x 4) cm volume of gold = 800 cm 3 = 0.0008 m 3 mass = volume x density = 0.0008 x 19 300 = 15.4 kg weight = 15.4 x 9.81 weight of gold ingot = 152 N

7. Answers densitymassvolume 240 g40 cm 3 3000 kg m -3 4500 kg 0.80 g cm -3 80 cm 3 9 kg0.003 m 3 6 g cm -3 3 g cm -3 1.5 m 3 64 g Complete:

8. Density and Pressure Notes questions from pages 162 to 168 1.Answer the questions on page 168. 2.Verify that you can do all of the items listed in the end of chapter checklist on page 168.

9. Online Simulations