A baseball is seen to pass upward by a window 24 m above the street with a vertical speed of 8 m/s. The ball was thrown from the street.

(a) What was its initial speed?
(b) What altitude does it reach?
(c) How long after it was thrown did it pass the window?

1 answer

(a) Try using conservation of energy

Mg*(24 m)+(1/2)M*(8 m/s)^2 = (1/2) M Vo^2

Cancel out the M's and solve for Vo.

2) Vo^2/(2 g)

3) How long does it take the velocity to go from Vo to 8 m/s?

(Vo -8)= g t

Solve for t