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 + \(\sqrt{( 2as)}\)}
jamb 1992mathematics

The correct answer is A. \(\frac{1}{a}\) (-u + \(\sqrt{U^2 - 2as}\))

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

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

∴ 2S = 2ut + at

= at

+ 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 + \(\sqrt{U^2 - 2as}\))

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