Old Isaac took a little nosedive from his perch on Mrs. Cohen’s window ledge 25 feet above ground. Given that he fell as a result of a gentle tap to his noggin, how fast is Isaac traveling when he hit’s the ground? (gravity is -32ft/sec^2).

25ft=½(32ft/sec^2)t^2
t=1.25sec

-32ft/sec=(vf - 0)/1.25s
Vf=-40ft/sec

1 answer

or you could have worked it ..

Vf^2=2*g*height
Vf= sqrt (2gh)=sqrt(2*32*25)=sqrt (1600)