Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 month ago

# Graphing Problem?

Sarah is a world-class diver in the women’s 3-m springboard competition. Her height, h (in metres), above the water t seconds after she leaves the board is given h=4.9t^2+8.8t+3 by . How long is Sarah in the air before she reaches the water? Make sure to round your answer to the nearest tenth. Hint: Try graphing the problem on your calculator.

### 3 Answers

Relevance
• 1 month ago

In order to simulate a real jump, the function should be:

h(t) = -4.9t² + 8.8t + 3

She reaches the water when h(t) = 0

i.e. when -4.9t² + 8.8t + 3 = 0

Using the quadratic formula we have:

t = [-8.8 ± √(8.8² - 4(-4.9)(3)]/-9.8

so, t = (-8.8 ± √136.24)/-9.8

Hence, t = 2.1 seconds

:)>

• Ash
Lv 7
1 month ago

Pope is correct about the error. You missed the negative sign for first term

h = -4.9t²+8.8t+3

When Sarah reaches the water h = 0

0 = -4.9t²+8.8t+3

Using quadratic solution

t = {-8.8±√[8.8² - 4(-4.9)(3)]}/(2*-4.9)

t = 2.1 s

• Pope
Lv 7
1 month ago

Yes, do try graphing it on your calculator. Are you quite certain of the formula you gave for height? Once she leaves the board, she will continue to rise, never to return to Earth.

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