A foul ball is hit straight up into the air with a speed of about 15 m/s. (b) How long is it in the air? sec?

Question

the one guy got the first part right this is the second part someone please help me its due tonite

Answer 1

Just double the time to reach apogee

0=15-gt to apogee
2*15/g is the total flight time.

If you want to prove it mathematically
y(t)=15*t-.5*g*t^2 without air resistance.

Set y(t)=0 and solve for t. You will have two answers:
t=0, that's the moment it was hit and
t=15*2/g
Plug that in and y(t)=0

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