It would be best to ask this question in the maths forum (and I'll request this thread to be moved).(Original post by azhar1932391)
A ball is projected vertically upwards, from a point X which is 7m above the ground, with speed 21m/s². Find the time of the flight of the ball.
But to get you started, you're going to use the SUVAT equations - where do you think you should start?
... and the ones that won't