Constant Acceleration Formulae

Understanding the Concept

Constant acceleration is a type of motion in which the velocity of an object changes by an equal amount in every equal time period.
A good example of constant acceleration is an object that falls freely under gravity (ignoring air resistance).

This topic usually covers five key formulae. The object’s displacement (s), initial velocity (u), final velocity (v), acceleration (a), and time (t) are related by these formulae.
First formula: final velocity, v = u + at.
Second formula: displacement, s = ut + 0.5at².
Third formula: final velocity squared, v² = u² + 2as.
Fourth formula: average velocity, Avg. v = (u + v) / 2.
Fifth formula: displacement without time, s = (u + v) / 2 * t.

These formulae are used to solve problems involving constant acceleration.
To use these formulae, first write out what quantities you know and what you need to find. Then, choose the formula that connects those quantities.
Sometimes, you might need to use two of the equations — one to find an intermediate quantity, and then another to find the final answer.

In these equations, displacement is measured in metres (m), velocity is measured in metres per second (m/s), acceleration is measured in metres per second squared (m/s^2) and time is measured in seconds (s).
Remember that these are the standard units in mechanics.

Constant acceleration formulae are not just theoretical; they are used in real-world contexts from car safety to rocket science.
For instance, they can be used to calculate the distance a car will travel when braking, which can assist in programming anti-lock braking systems (ABS).