an athletic facility is building an indoor track. the track is composed of a rectangle and two semicircles, as shown. a) write a
formula fir the perimeter of the indoor track. b) solve the formula for x. c) the perimeter of the track is 660 feet, and r is 50 feet. find x. round your answer to the nearest foot.
1 answer:
Answer:
(a) P = 2x + 2r + 2πr
(b) x = ½(P - 2r - 2πr)
(c) x = 123 feet
Step-by-step explanation:
See Attachment for sketch of the track
Solving for (a): Perimeter of the track
This is calculated by adding the perimeter of the rectangle to the 2 semicircles as follows.
P = Perimeter of Rectangle + Perimeter of 2 Semicircles
P = 2(x + r) + 2 * πr
[Where r is the radius of both semicircles]
Open bracket
P = 2x + 2r + 2πr
Solving for (b): Formula for x
P = 2x + 2r + 2πr
Make x the subject of formula
2x = P - 2r - 2πr
Divide both sides by 2
x = ½(P - 2r - 2πr)
Solving for (c): the value of x when r = 50 and P = 660
Substitute the given values in the formula in (b) above
x = ½(P - 2r - 2πr)
x = ½(660 - 2 * 50 - 2π * 50)
x = ½(660 - 100 - 100π)
x = ½(560 - 100π)
Take π as 3.14
x = ½(560 - 100 * 3.14)
x = ½(560 - 314)
x = ½ * 246
x = 123 feet
You might be interested in
<h3>The distance between two landmarks is 123 meters</h3>
<em><u>Solution:</u></em>
We have to find the distance between two landmarks
<em><u>Use the law of cosines</u></em>
The third side of a triangle can be found when we know two sides and the angle between them
Here, angle between 90 meters and 130 meters is 65 degrees
From figure,
a = 90
b = 130
c = d
Therefore,
Thus, the distance between two landmarks is 123 meters
Answer:
your answer will be
Step-by-step explanation:
hope this helps have a nice day :)
Answer:
0.0314 = 3.14% probability that it takes at most 1 hour of machining time to produce a randomly selected component
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation
, the z-score of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Sum of normal variables:
When normal variables are added, the mean is the sum of the means while the standard deviation is the square root of the sum of the variances.
The mean values are 20, 15, and 30 min, respectively:
This means that
The standard deviations are 1, 2, and 1.5 min, respectively.
This means that
What is the probability that it takes at most 1 hour of machining time to produce a randomly selected component?
Mean and standard deviation are in minutes, so this is the pvalue of Z when X = 60.
has a pvalue of 0.0314
0.0314 = 3.14% probability that it takes at most 1 hour of machining time to produce a randomly selected component