When a flare is fired upward at 58.8 m/s, its height, h meters, is given by the equation h=-4.9t^2 + 58.8t, where t seconds is the time since firing. how long will it take for the false to hit the ground?

Question

campbell_st · Answer

well solve for t by letting h = 0

so 

$$-4.9t^2 + 58.8t$$

can be factored... 

one value of t will be zero... initial height at leaunch was zero

find the time when the it hits the ground again, and you have the flight time...