A particle moves in a straight line with a constant acceleration. It changes its velocity from $10\ ms^{- 1}$to $20\ ms^{- 1}$ while passing through a distance $135\ m$ in $t$ second. The value of $t$ is

Question

Dr. Abubacker · Accepted Answer

(b) $v^{2} = u^{2} + 2as$
$a = \frac{v^{2} - u^{2}}{2s} = \frac{(20)^{2} - (10)^{2}}{2 	imes 135} = \frac{300}{270} = \frac{10}{9}m/s^{2}$
From first equation of motion
$v = u + at \Rightarrow t = \frac{v - u}{a} = \frac{20 - 10}{10/9} = \frac{10}{10/9} = 9\ sec$

Q. A particle moves in a straight line with a constant acceleration. It changes its velocity from $10\ ms^{- 1}$to $20\ ms^{- 1}$ while passing through a distance $135\ m$ in $t$ second. The value of $t$ is

Explanation

Reviewed by Dr. Abubacker

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