Level: Secondary Class: 9 Subject : PHYSICS Physics – Text Book Board Unit 1 Physical Quantities and Measurement Topic 1. Physical quantities/International System of units/Prefixes Work sheet 1. How can you differentiate between base and derived quantities? 2. Identify the base quantity in the following: (i) Speed (ii) Area (iii) Force (iv) Distance 3. Identify the following as base or derived quantity: density, force, mass, speed, time, length, temperature and volume.