## Overview This topic covers units, dimensions, basic ideas on scalar and vector quantities and the differences between them. The basic physics in this unit gives learners the ideas and skills they need to progress to further study of Newtonian mechanics, kinetic theory and thermal physics. ## Working Scientifically The specified practical work in this topic gives learners the opportunity to use apparatus to record a range of measurements and to interpolate between scale readings. Learners also have the opportunity to follow written instructions, to make and record observations, keep appropriate records and present information and data in a scientific way. ## Mathematical Skills There are a number of opportunities for the development of mathematical skills in this unit. These include identifying the correct units for physical quantities; using physical constants expressed in standard form; using ratios, fractions and percentages; using calculators to handle trigonometrical expressions; calculating mean values for repeated experimental readings. ## How Science Works There are opportunities within this topic for learners to carry out experimental and investigative activities, including appropriate risk management, in a range of contexts. ### Learners should be able to demonstrate and apply their knowledge and understanding of: (a) the 6 essential base SI units (kg, m, s, A, mol, K) (b) representing units in terms of the 6 base SI units and their prefixes (c) checking equations for homogeneity using units (d) the difference between scalar and vector quantities and to give examples of each – displacement, velocity, acceleration, force, speed, time, density, pressure etc (e) the addition and subtraction of coplanar vectors, and perform mathematical calculations limited to two perpendicular vectors (f) how to resolve a vector into two perpendicular components (g) the concept of density and how to use the equation m V  = to calculate mass, density and volume (h) what is meant by the turning effect of a force (i) the use of the principle of moments (j) the use of centre of gravity, for example in problems including stability: identify its position in a cylinder, sphere and cuboid (beam) of uniform density (k) when a body is in equilibrium the resultant force is zero and the net moment is zero, and be able to perform simple calculations ## [[Specified Practical Work ]] - [[Measurement of the density of solids]] - [[Determination of unknown masses by using the principle of moments]]