Make t the subject of formula S = ut + \(\frac{1}{2} at^2\)

A.

\(\frac{1}{a}\) (-u + \(\sqrt{U^2 - 2as}\))

B.

\(\frac{1}{a}\) {u \(\pm\) (U2 - 2as)}

C.

\(\frac{1}{a}\) {u \(\pm\) \(\sqrt{2as}\)}

D.

\(\frac{1}{a}\) {-u + \(\sqrt{( 2as)}\)}

Correct answer is A

Given S = ut + \(\frac{1}{2} at^2\)

S = ut + \(\frac{1}{2} at^2\)

∴ 2S = 2ut + at2

= at2 + 2ut - 2s = 0

t = \(\frac{-2u \pm 4u^2 + 2as}{2a}\)

= -2u \(\pi\) \(\frac{\sqrt{u^2 4u^2 + 2as}}{2a}\)


= \(\frac{1}{a}\) (-u + \(\sqrt{U^2 - 2as}\))