# Question #cb30b

Mar 6, 2017

(a) Using the kinematic expression
${v}^{2} - {u}^{2} = 2 a s$ and inserting given values in SI units we get
${v}^{2} - {\left(7.0\right)}^{2} = 2 \times 0.71 \times 1033$
${v}^{2} = 49 + 2 \times 0.71 \times 1033$
$v = \sqrt{49 + 2 \times 0.71 \times 1033} = 38.9 m {s}^{-} 1$, rounded to one decimal plave

(b) We can use the following kinematic expression here
$v = u + a t$
as velocity $v$ is attained after moving a distance of $1.033 k m$
$\implies t = \frac{v - u}{a}$ and inserting given values we get
$t = \frac{38.9 - 7.0}{0.71} = 45 s$ rounded to nearest second.