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An object is launched at 29.4 meters per

second (m/s) from a 34.3-meter tall

platform. The equation for the object's

heights at time x seconds after launch is

f(x) = -4.9x2 +29.4x+ 34.3, where y is in

meters. What is a reasonable domain for

this scenario?

a [0,7]

b [0, 34. 3]

c [0,00)

d(-00,00)

User Strickland
by
4.9k points

1 Answer

2 votes

Answer:

The reasonable domain for the scenario is option 'a';

a) [0, 7]

Explanation:

For the projectile motion of the object, we are given;

The speed at which the object is launched, v = 29.4 meters per second

The height of the platform from which the object is launched, h = 34.3 meter

The equation for the height of the object as a function of time 'x' is given as follows;

f(x) = -4.9·x² + 29.4·x + 34.3

The domain for the scenario, is given by the possible values of 'x' for the function, which is found as follows;

At the height from which the object is launched, x = 0, and f(x) = 34.3

At the ground level to which the object can drop, f(x) = 0

∴ f(x) = -4.9·x² + 29.4·x + 34.3 = 0

-4.9·x² + 29.4·x + 34.3 = 0

By the quadratic formula, we have;

x = (-29.4 ± √(29.4² - 4 × (-4.9) × 34.3))/(2 × (-4.9)

∴ x = -1, or 7

Given that time is a natural number, we have the reasonable domain for the scenario as the start time when the object is launched, t = 0 to the time the object reaches the ground, t = 7

Therefore, the reasonable domain for the scenario is; 0 ≤ x ≤ 7 or [0, 7].

User Lazar Kukolj
by
4.4k points