A rocket is fired vertically upwards with a net acceleration of `4 m//s^2` and initial velocity zero. After `5s` its fuel is finished and it decelerates with g. At the highest point its velocity becomes zero. Then, it accelerates downwards with acceleration g and return back to ground. Plot velocity-time and displacement -time graphs for the complete journey. Take `g=10m//s^2.`

Answer

A

Explanation

Here `a_(x)/a_(y)=(g cot theta)/g=1/(tan theta)=u_(x)/u_(y)rArr` Initial velocity & acceleration are opposite to each other.
`rArr` Ball will return to point O.