Problema Solution

If a metal ball is thrown downward with an initial velocity of 22 feet per second (15 mph) from a 100 foot water tower its height h in feet above the ground after t seconds. Determine symbolically when the geight of the ball is 62 feet.

Answer provided by our tutors

h(t)=-16t^2-22t+100 

62=-16t^2-22t+100

-16t^2-22t+38=0

-8t^2-11t+19=0

solve by following quadratic formula

..

a=-8, b=-11, c=19

t=[-(-11)+-sqrt(-11)^2-4*-8*19)]2*-8

t=[11+-sqrt(729)]/16=(11+-27)/-16

t=-16/-16=1 

t=38/-16=-2.375 (reject, t=>0)

ans:

The height of the ball is 62 feet above the ground after 1 second