When may suvat be used?

Only when acceleration is constant.

How derive v=u+at with calculus?

v=\int a\,dt=at+c, with v=u at t=0.

Two objects meet when?

Their displacements from the same point are equal.

Constant acceleration (suvat) equationsEdexcel A-Level Maths: Flashcards

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Five suvat variables?

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Five suvat variables?: $s$ displacement, $u$ initial velocity, $v$ final velocity, $a$ acceleration, $t$ time.
Equation with no $s$ ?: $v=u+at$
Equation with no $v$ ?: $s=ut+\frac12at^2$
Equation with no $t$ ?: $v^2=u^2+2as$
Equation with no $a$ ?: $s=\frac12(u+v)t$
Equation with no $u$ ?: $s=vt-\frac12at^2$
What does the gradient of a $v$ -- $t$ graph give?: Acceleration.
What does the area under a $v$ -- $t$ graph give?: Displacement.
When may suvat be used?: Only when acceleration is constant.
Value and direction of $g$ ?: $9.8$ m s $^{-2}$ downwards.
Velocity at the highest point of a vertical throw?: $v=0$
If an object returns to its starting level, what is $s$ ?: $s=0$
How derive $v=u+at$ with calculus?: $v=\int a\,dt=at+c$ , with $v=u$ at $t=0$ .
Two objects meet when?: Their displacements from the same point are equal.

Exam questions on Constant acceleration (suvat) equations

A ball is thrown vertically upwards from ground level with speed $14$ m s $^{-1}$ . The ball is modelled as a particle moving freely under gravity, with $g=9.8$ m s $^{-2}$ and upwards taken as positive.
Find the speed of the ball 1.5 s after it is thrown, and state whether it is moving upwards or downwards.2 marks
A car brakes with constant deceleration from a speed of $30$ m s $^{-1}$ and comes to rest after travelling 90 m in a straight line.
Find the distance the car travels in the first 2 s of braking.2 marks
A particle moves in a straight line with constant acceleration $a$ m s $^{-2}$ . At $t=0$ its velocity is $u$ m s $^{-1}$ . At time $t$ seconds its velocity is $v$ m s $^{-1}$ and its displacement from its starting point is $s$ metres.
Using the fact that the area under a velocity--time graph is the displacement, show that $s=ut+\frac12at^2$ .3 marks

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Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).