Question

A catapult launches a boulder with an upward velocity of 112 ft/s. The height of the boulder, h, in feet after t seconds is given by the function h= -16t^2 + 112t + 30 .
How long does it take the boulder to reach its maximum height? What is the boulder’s maximum height? Round to the nearest hundredth, if necessary.

Answer 1

A. 7 s; 30 ft
B. 3.5 s; 366 ft
C. 3.5 s; 618 ft
D. 3.5 s; 226 ft

Answer 2

is this precal

Answer 3

use the vertex formula

Answer 4

@baldymcgee6 how do I do that

Answer 5

-b/2a

Answer 6

can u use calculator

Answer 7

D

Answer 8

D. 3.5 s; 226 ft

Answer 9

i am sure

Answer 10

WIth the calculator what would I divide or Minus?

Answer 11

is this for a calculus class or not?

Answer 12

i think it is not @baldymcgee6

Answer 13

you don't know what class you're in? haha

Answer 14

Its Algebra 2

Answer 15

r u adressing me

Answer 16

use calculator

Answer 17

find max point

Answer 18

How @ksaimouli, i wrote everything into the calculator and I got -114 that is not correct answer

Answer 19

-b/2a = -112/2(16) = 3.5 s

t= 3.5s

h = -16t^2 + 112t + 30
h = -16(3.5)^2 +122(3.5) +30
h = 226

Answer 20

adjust the windows to y=300

Answer 21

@chicagochica5 i told you how, use the vertex formula, and this will give you the time at which it is at its maximum

Answer 22

say 2nd and calc and press find max

Answer 23

@ksaimouli, Just I have a phone calculator

Answer 24

@baldymcgee6 is that formula used in calculus

Answer 25

@chicagochica5 it is better to do it by hand, @ksaimouli is suggesting you use a graphing calculator, which is totally possible and easier, but it doesn't help you learn and sometimes you are not allowed a calculator.

Answer 26

no u should have ti-83

Answer 27

yup u r right

Answer 28

@ksaimouli some classes do not allow a graphing calculator such as the ti 83, and no it definitely not a calculus formula.

Answer 29

but i confuses when we say another and their teacher says totally different

Answer 30

its simply a parabolic formula to find the vertex of a parabola.

Answer 31

Thanks @ksaimouli and @baldymcgee6

Answer 32

welcome

Answer 33

you are welcome @chicagochica5