A hang glider dropped his cell phone from a height of 350 feet. How many seconds did it take for the cell phone to reach the ground?

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Answer 1 · 2018-06-17T21:53:53

#t = 4.68 s#

Assuming negligible air drag, it was in free fall (g = 32 ft/s^2) for the entire 350 feet. So we use the formula

#y = u*t + 1/2*a*t^2#

Plugging in the data

#350 ft = 0 + 1/2*(32 "ft")/s^2*t^2#

#350 ft = (16 ft)/s^2*t^2#

#t^2 = (350 cancel(ft))/((16 cancel(ft))/s^2) = 21.88 s^2#

#t = sqrt(21.88 s^2) = 4.68 s#

I hope this helps,
Steve