Hi I need to make t subject
S=ut+ 1/2(at^2)
I worked it out(last line) = 2s-2ut/at = t^2/t =t
Is this correct?
Not quite because you need to have t and only t on the right
$\displaystyle s = ut+\frac{1}{2}at^2 \: \: \rightarrow \: \: at^2+2ut-2s=0$
Use the quadratic equation to get an expression for $\displaystyle t$
The Kinematic Equations comes up in all fields
[QUOTE=wolfhound;418431]You could complete the square
$\displaystyle at^2+2ut=2s$
Divide by a
$\displaystyle t^2+\frac{2u}{a}t = \frac{2s}{a}$
$\displaystyle \left(t+\frac{u}{a}\right)^2 - \frac{u^2}{a^2} = \frac{2as}{a^2}$
$\displaystyle \left(t+\frac{u}{a}\right)^2 = \frac{2as+u^2}{a^2}$
$\displaystyle \left(t+\frac{u}{a}\right) = \pm \frac{\sqrt{2as+u^2}}{a}$
$\displaystyle t = \frac{-u\pm \sqrt{2as+u^2}}{a}$