Motion in a Straight Line

Assertion A body is momentarily at rest at
the instant, if it reverse the direction.
Reason A body cannot have acceleration, if
its velocity is zero at a given instant of time.

In an experiment to measure the height of a bridge by dropping stone into water underneath. If the error in measurement of time is \(0.2 \mathrm{~s}\) at the end of \(4 \mathrm{~s}\), then the error in estimation of height of bridge will be...

What will be the a vs x graph for the following
graph?