Answer:
13.98 in²
Step-by-step explanation:
I don't understand it, either.
Point N is part of a "segment" that above and to the right of chord MO. It is the sum of the areas of 3/4 of the circle and a right triangle with 7-inch sides. The larger segment MO to the upper right of chord MO has an area of about 139.95 in², which <u>is not</u> an answer choice.
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The remaining segment, to the lower left of chord MO does not seem to have anything to do with point N. However, its area is 13.98 in², which <u>is</u> an answer choice. Therefore, we think the question is about this segment, and we wonder why it is called MNO.
The area of a segment is given by the formula ...
A = (1/2)(θ -sin(θ))r² . . . . . . where θ is the central angle in radians.
Here, we have θ = π/2, r = 7 in, so we can compute the area of the smaller segment MO as ...
A = (1/2)(π/2 -sin(π/2))(7 in)² = 24.5(π/2 -1) in² ≈ 13.9845 in²
Rounded to hundredths, this is ...
≈ 13.98 in²
Answer:
10.69
Step-by-step explanation:
We must first know that the angle of refraction is given by the following equation:
n_water * sin (A_water) = n_air * sin (A_air)
where n is the refractive index, for water it is 1.33 and for air it is 1.
The angle (A) in the air is 22.8 °, and that of the water is unknown.
Replacing these values we have to:
1.33 * sin (A_water) = 1 * 0.387
sin (A_water) = 1 * 0.387 / 1.33
A_water = arc sin (0.2907) = 16.9 °
now for the tank depth:
h = D / tan (A_water)
D = 3.25
Replacing
h = 3.25 / tan 16.9 °
h = 10.69
Therefore the depth is 10.69 meters.
Hi!
I think Grace needs to wash at least 6 cars. Please tell me if I'm wrong.
Thank you
