Enter any 3 known SUVAT variables and instantly calculate the unknowns. Perfect for GCSE and A-Level Physics revision.
How to use:
Enter exactly 3 known values and the calculator will find the remaining 2 unknowns with full working shown.
Fill in any 3 known SUVAT values to see the solution with full working.
Relates velocity and time
Displacement without final velocity
Displacement without initial velocity
Relates velocities and displacement
Average velocity method
Write down all the SUVAT values given in the question. Include starting from rest (u = 0) or coming to a stop (v = 0).
Decide which direction is positive. Usually upward or forward is positive. Deceleration means negative acceleration.
Convert all values to SI units before calculating. Divide km/h by 3.6 to get m/s. Time must be in seconds.
The five SUVAT equations are: (1) v = u + at, (2) s = ut + ½at², (3) s = vt - ½at², (4) v² = u² + 2as, and (5) s = ½(u + v)t. Each equation relates four of the five kinematic variables, allowing you to solve problems when you know any three.
SUVAT is an acronym representing the five variables in kinematic equations: S = displacement (metres), U = initial velocity (m/s), V = final velocity (m/s), A = acceleration (m/s²), and T = time (seconds). These equations only apply when acceleration is constant.
First, identify which three variables you know and which one you need to find. Then select the equation that contains all four of these variables. For example, if you know u, a, t and need v, use v = u + at. This calculator automatically selects the correct equation for you.
SUVAT equations only work when acceleration is constant (uniform acceleration). Common examples include free fall under gravity, objects sliding down slopes, and vehicles braking with constant force. They cannot be used for circular motion or variable acceleration.
When using v² = u² + 2as, taking the square root can give positive and negative answers. The correct answer depends on the direction of motion. If an object is moving forward, velocity is positive; if backward (e.g., bouncing back), it's negative. Consider the physical situation.
Negative acceleration (deceleration) occurs when an object slows down in the positive direction, or speeds up in the negative direction. For example, a car braking while moving forward has negative acceleration. Always define your positive direction first.
For GCSE Physics, some equations like v² = u² + 2as are provided, but v = u + at and s = ut + ½at² must be memorised (AQA). For A-Level, all equations are typically provided. Check your exam board's formula sheet.
Divide by 3.6 to convert km/h to m/s. For example, 72 km/h ÷ 3.6 = 20 m/s. To convert m/s to km/h, multiply by 3.6. Always use m/s for SUVAT calculations to get correct units in your answer.
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