Question

A stone is thrown vertically upwards with a velocity of 39.2m/s.how much time will take to attain the maximum hieght

Answer 1

t =
$\frac{v - u}{a}$
here v = 0 (since at maximum height, the ball will stop)
u = 39.2
and a = -9.8m/s² (acceleration due to gravity and acting in opposite directions hence is negative)

so t =
$\frac{0 - 39.2}{ - 9.8} \\ = \frac{ - 39.2}{ - 9.8} \\ = 4$
hence time taken = 4s


Hope it helps dear friend ☺️