Question

A model rocket is launched with an initial upward velocity of 65/ms . The rocket's height h (in meters) after t seconds is given by the following. h=65t-5t^2 Find all values of t for which the rocket's height is 25 meters. Round your answer(s) to the nearest hundredth. (If there is more than one answer, use the "or" button.) ground h

Answer 1

t≈0.40

t≈12.6

Explanation:

h=65t-5t^2

Let h = 25

25=65t-5t^2

Subtract 25 from each side

25-25=-25 +65t-5t^2

0 = -5t^2 +65t -25

Using the quadratic formula

where a =- 5 b= 65 and c=-25

-b ± sqrt (b^2 -4ac)

-----------------------------

2a

-65 ± sqrt (65^2 -4(-5)(-25))

-----------------------------

2(-5)

-65 ± sqrt (4225 -250))

-----------------------------

-10

-65 ± sqrt (3975))

-----------------------------

-10

t≈0.39672

t≈12.603

Rounding to the nearest hundredth

t≈0.40

t≈12.6

Answer 2

- - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - -

➷
`65t - 5t^(2) = 25`

Minus 56 and add
`5t^(2)` to both sides

`5t^(2) - 65t + 25 = 0`

Divide by 5 to get
`t^(2)`

`t^(2) -13t+5 = 0`

Substitute these values into the quadratic equation to give you the answers:

0.40s and 12.60s

➶Hope This Helps You!

➶Good Luck :)

➶Have A Great Day ^-^

↬ Hannah ♡