An explosives company specializes in bringing down old buildings. The time it takes for a particular piece of flying debris to fall to the ground can be modelled by the function h(t)= -12(t+2)^2 + 120(t+2), where h is the height of the debris in metres and t is the time in seconds.

Question

1.) How long will it take for the piece of debris to hit the ground after an explosion? Show all work

Answer 1

is there something unclear about the solution at

http://www.jiskha.com/display.cgi?id=1464662427

??