Answer:
The ball must be tossed to a height of 4 times the initial height H
Explanation:
We have equation of motion S = ut + 0.5at²
A juggler tosses balls vertically to height H.
That is
H = 0 x t + 0.5 x a x t²
H = 0.5at²
To what height must they be tossed if they are to spend twice as much time in the air.
H' = 0 x 2t + 0.5 x a x (2t)²
H' = 2at² = 4 H
So the ball must be tossed to a height of 4 times the initial height H