1. Standards of Measurement

2. Not my own Power Point, taken from scienceplanet.wikispaces.com/file/.../(1- 2)+Standards+of+measurement.p...

3. Standard: Look at this roll of string: 150 what? 150 ft? 150 cm? 150 m? Measurement = Number + Unit Standard unit: what all people agree on and understand. 150

4. System of Measurement English System USA ft, mile, pound… Meter System Most of the world. m, kg, cm, N… The basis for the SI International System of Units (International Bureau of Weights & Measurements in Sevres, France) Both systems are equally accurate.

9. Page 16

10. Measuring Distance (Length): Length is the distance between two points. SI base unit for length is m We need to use different unites sometimes: – cm for things like a pencil – Km for long distances like between RAK and Dubai. Remember: – 1m = 100 cm – 1Km = 1000 m – 1cm = 10 mm – 1dm = 10 cm

11. Measuring Volume Volume: the amount of space occupied by an object. You’ll learn how to measure the volume of: 1.Regular solids, like a cube. 2.Liquids. 3.Irregular solids, like a pencil or a crown. Ms. Rania Abdelbaqi - IAT/RAK

12. 1.Volume of regular solids: Ex: a cube V = l x w x h = 5 cm x 5 cm x 5 cm = 125 cm 3 Where cm 3 is a volume unit.

13. 2.Volume of liquids: -By graduated cylinders. -Most common units are 1 mL = 1 cm 3 1 L = 1 dm 3 - Ex: how many cubic centimeters are in 1.5L? (check your note book for the answer)

14. 3. Volume of irregular solids: These are the things that don’t have regular sides to measure. Their volume can be measured by water displacement method. (→ next slide)

15. 1.Read the volume of water before immersing the crown in water. 2000 mL 2300 mL 2. Read the volume of water after immersing the crown in water. 3. The difference in the water volume, is the volume of the crown. (300 mL)

16. Measuring Mass Mass : How much matter in an object. Units: kg, g, mg, …. Remember: 1 kg = 1000 g 1g = 1000 mg Example: how many kilograms are in 6430 mg? (check your copy book for the answer)

17. Density : is the mass per unit volume. Density = What is the density of an object having a mass of 10g and a volume of 2 cm 3 ? Density = = 5 g/cm 3 The unit of density is g/cm 3