Problema Solution

A ball is thrown downward from the top of a 180 foot building with an initial velocity of 20 feet per second. The height (h) after (T) seconds is given by the equation h=-16t^2 -20t +180. How long after the ball is thrown willl it reach the ground

Answer provided by our tutors

the ball will reach the ground when h = 0 for some t, t>0 (the time can not be negative)


by solving the equation:


-16t^2 -20t +180 = 0


we find


t = 2.79 sec


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the ball will reach the ground in 2.79 seconds.