Answer
a). $a_{u}=0.55m/s^{2}$
$a_{d}=0.20m/s^{2}$
b). Time taken more while coming down $=40.61s$
Work Step by Step
a). $v^{2}=u^{2}+2aS$
So, For up motion, 1008m/min=16.8m/s
So, $a_{u}=\frac{16.8^{2}}{509}=0.55m/s^{2}$
For down motion, 610m/min=10.17m/s
So, $a_{d}=\frac{10.17^{2}}{509}=0.20m/s^{2}$
b). Time for upwards motion $=2\times \frac{16.8}{0.55}=61.09s$
Time for downwards motion $=2\times \frac{10.17}{0.2}=101.7s$
So, time taken more while coming down $= 101.7-61.09=40.61s$
