Q:

PLEASE HELP If a football player passes a football from 4 feet off the ground with an initial velocity of 36 feet per second, how long will it take the football to hit the ground? Use the equation h = βˆ’16t^2 + 6t + 4. Round your answer to the nearest hundredth.A) 0.72B) 0.65C) 0.35D) 0.27

Accepted Solution

A:
Answer: Β  A) Β 0.72Step-by-step explanation:You want to find t when h = 0, so you're solving ... Β  0 = -16t^2 +6t +4The quadratic formula tells you the solution is ... Β  t = (-b +√(bΒ² -4ac))/(2a) . . . . . . where you have a=-16, b=6, c=4 Β  t = (-6 -√(36 -4Β·(-16)Β·4))/(2(-16)) = (-6 -√292)/-32 Β  t β‰ˆ 0.7215 β‰ˆ 0.72 . . . . seconds_____Comment on the problem statementIt appears the velocity number of 36 ft/s is irrelevant, as the equation tells you the initial upward speed of the ball is 6 ft/s.