question_answer

A car moving on a road with uniform acceleration covers 20m in the first second and 30m in the next second. Find the acceleration of the car.

Answer:

\[{{s}_{n}}=u+\frac{a}{2}(2n-1)\] \[20=u+\frac{a}{2}(2-1)\]                             \[(\because n=1s)\] \[20=u\frac{a}{2}\]                                          ………….. (1) \[30=u+\frac{a}{2}(2\times 2-1)\]                             \[(\because n=2s)\] \[30=u+\frac{3a}{2}\]                                     ………… (2) Solving (1) & (2) for ‘a’, \[\frac{\begin{align}   & 30=u+\frac{3a}{2} \\  & 20=u+\frac{a}{2} \\ \end{align}}{10=a}\] \[\because a=10m{{s}^{-2}}\]