Question

Brandon hit a baseball upward with an initial speed of 120 feet per second. How much later did Ollie catch the ball? Use the formula h = -16t squared + vt.

Answer 1

h = -1 6 t ^ 2 + vt

v = 120


h = - 16 t ^ 2 + 120 t

h = - 4 * 4 t ^ 2 + 4 * 30 t

h = 4 t ( - 4 t + 30 )


0 = 4 t ( - 4 t + 30 )

obviously solution :

t = 0

( initial point )


and

- 4 t + 30 = 0

- 4 t = - 30

- 4 t / 4 = - 30 / - 4

t = 30 / 4 = 2 * 15 / ( 2 * 2 ) = 15 / 2 = 7.5 s

Answer 2

hello :) i am an adv. algebra student and i often struggle w my homework, so i'd like to help those who are struggling with this problem. the formula for calculating maximum height is as follows: h=rt-16t^2. define your variables in a "let" statement and proceed by substituting as many variables as possible with information provided in the text. since we know the rate is 120 ft/s we can replace the "r." then you factor out the GCF to get "h=4t(30-4t)." if you distribute the "4t" you will get "h=120t-16t^2" which is the original equation. replace the "h" with a zero since solving for "h"--zero--is the goal. obviously "30-4t" has to equal zero so when you multiply that set of parenthesis by the outside "4t" you get zero. so since "30-4t" must equal zero, 30 and 4t must be equal to one another. so set up the equation: "30/4=4t/4" and solve for the variable "t." if you divided correctly, you should have written "t=7.5secs." hope i helped!!