Question

a ball is thrown upwards at a velocity of 20.2m/s at what time will the ball reach its highest point

Answer 1

Use the equation
$vf = vo + a \times t$
plug in the variables for the equation. Use 0 for Vf because at the highest point the velocity would be zero. Use -9.8 for acceleration because that is the speed at which gravity pulls down.
$0 = 20.2 + ( - 9.8) \times t$
your answer would be 2.06122 seconds.