Question

A firecracker shoots up from a hill 150 feet high, with an initial speed of 110 feet per second. Using the formula H(t) = −16t2 + vt + s, approximately how long will it take the firecracker to hit the ground?

Eight seconds
Nine seconds
10 seconds
11 seconds

Answer 1

@LiveLaughDie @Nnesha @pooja195

Answer 2

what is s?

Answer 3

im not sure @sohailiftikhar

Answer 4

it should be some constant value like 5,3 etc u checked the statement clearly ?

Answer 5

take is 5 ..now out height H=0 to find the time
0=-16t^2+vt+5

Answer 6

now 16t^2-vt=5
put value of v from given data v=110fet/sec
16t^2-110t=5 divide whole equation with 16 to get simplest form

Answer 7

16t^2=5+110
16T^2=115
is tis correct?

Answer 8

no where is the t with 110 ?

Answer 9

? could you just show me for my understudying @sohailiftikhar

Answer 10

just find the value of t from the equation which i gave you ignor negative value and get +ve value that will be the answer

Answer 11

t=2.680951

Answer 12

@sohailiftikhar

Answer 13

did u do your work correctly ? what two values you have got ? for t

Answer 14

-2.680951

Answer 15

there ya goooo @sohailiftikhar

Answer 16

ok it's correct

Answer 17

ok I'm still not sue what the answer is :/ @sohailiftikhar

Answer 18

lol we are not sure about s which we taken as 5 ..so take it easy it's 2 sec

Answer 19

that not one of the answers :( @sohailiftikhar

Answer 20

so what is answer ?O.o

Answer 21

10? @sohailiftikhar

Answer 22

lol what ? no it can be possible it only can 2 or near it your answer is correct i'm sure ..from where u get this huh ?

Answer 23

here are the options:

Eight seconds
Nine seconds
10 seconds
11 seconds

Answer 24

setup the equation
when it hits the ground h(t)=0
n v=110
and s=150
now plug in the numbers and solve the qudratic equation

Answer 25

ok

Answer 26

so im solving for s?

Answer 27

no solve for t
they already gave you v and s value

Answer 28

what are they ?

Answer 29

\(\color{blue}{\text{Originally Posted by}}\) @Nnesha
setup the equation
when it hits the ground h(t)=0
n v=110
and s=150
now plug in the numbers and solve the qudratic equation
\(\color{blue}{\text{End of Quote}}\)
read this

Answer 30

ook so what would the formula be to solve for t ?

Answer 31

\[\huge\rm \frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }\] quadratic formula

Answer 32

a , b ,c values are \[\huge\rm Ax^2+Bx+C=0\]
A= leading coefficient
b=middle term
c= constant term