Equations of uniform acceleration
For steady acceleration: v squared = u squared + 2as, where u is start velocity, v is end velocity, a is acceleration and s is distance.
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Analogy
A recipe that links four ingredients: if you know three, you can find the fourth.
Example
u = 0, a = 2 m/s squared, s = 25 mv squared = 0 + 2 x 2 x 25v squared = 100v = 10 m/s
In practice
Used to work out stopping distances, or how long a runway a plane needs.
Questions people ask
When can I use v squared = u squared + 2as?
Use it only when acceleration stays constant, and the motion is in a straight line. It links start velocity, end velocity, acceleration and distance, with no time needed. If the acceleration is changing, the equation gives wrong answers. Check both conditions before you start.
How do I choose the right motion equation?
Write down what you know and what you want. List u, v, a, s and t. Pick the equation that contains your three known values and the one you want to find. If time is missing, v squared = u squared + 2as is usually the right choice.