Formulae and Kinematics

Substitution into Formulae

Rearranging Formulae

Kinematics Formulae

Rearranging Formulae by Factorising

Prerequisite Knowledge

• Solve linear equations in one unknown algebraically (including those with the unknown on both sides of the equation)
• Translate simple situations or procedures into algebraic expressions
• Deduce expressions to calculate the nth term of linear sequence
• Use compound units such as speed, rates of pay, unit pricing, density and pressure

Success Criteria

• Substitute numerical values into formulae and expressions, including scientific formulae
• Understand and use the concepts and vocabulary of expressions, equations, formulae, identities inequalities, terms and factors
• Understand and use standard mathematical formulae; rearrange formulae to change the subject
• Use relevant formulae to find solutions to problems such as simple kinematic problems involving distance, speed and acceleration
• Know the difference between an equation and an identity; argue mathematically to show algebraic expressions are equivalent, and use algebra to support and construct arguments

Key Concepts

• When substituting known values into formulae it is important to follow the order of operations.
• Students need to have a secure understanding of using the balance method when rearranging formulae. Recap inverse operations, e.g. x² => √x;.
• When generating formulae it is important to associate mathematical operations and their algebraic notation with key words.
• Sketching a diagram to model a motion enables students to identify the key information and choose the correct Kinematic formula.

Common Misconceptions

• Students often consider 2a³; to be incorrectly calculated as (2a)³;. Recap the order of operations to avoid this.
• Students often have difficulty generating formulae from real life contexts. Encourage them to carefully break down the written descriptions to identify key words.
• Knowing which kinematics formula to use often causes students to drop mark in examinations.
• When factorising terms students often forget to use the highest common factor.