Mr. Moore's physics class built different-shaped parachutes to see which shapes were more effective. The students tested the par
achutes by dropping them
from a height of 30 feet and timing the fall. They calculated the summary below:
The students wanted to see what happens to their times when they drop the parachutes from 45 feet. They find that every drop is increased by 2.5 seconds.
Find the new mean and standard deviation.
O Mean, 3.1 seconds; standard deviation, 0.6 second
O Mean, 5.6 seconds; standard deviation, 3.1 seconds
O Mean, 5.6 seconds; standard deviation, -1.9 seconds
O Mean, 8.1 seconds, standard deviation, 0.6 second
from a height of 30 feet and timing the fall. They calculated the summary below:
The students wanted to see what happens to their times when they drop the parachutes from 45 feet. They find that every drop is increased by 2.5 seconds.
Find the new mean and standard deviation.
O Mean, 3.1 seconds; standard deviation, 0.6 second
O Mean, 5.6 seconds; standard deviation, 3.1 seconds
O Mean, 5.6 seconds; standard deviation, -1.9 seconds
O Mean, 8.1 seconds, standard deviation, 0.6 second
1 answer:
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Answer:
Step-by-step explanation:
Start by noticing that the angle is on the 4th quadrant (between
and
. Recall then that in this quadrant the functions tangent and cosine are positive, while the function sine is negative in value. This is important to remember given the fact that tangent of an angle is defined as the quotient of the sine function at that angle divided by the cosine of the same angle:
Now, let's use the information that the tangent of the angle in question equals "-1", and understand what that angle could be:
The particular special angle that satisfies this (the magnitude of sine and cosine the same) in the 4th quadrant, is the angle
which renders for the cosine function the value .
Now, since we are asked to find the value of the secant of this angle, we need to remember the expression for the secant function in terms of other trig functions:
Therefore the value of the secant of this angle would be the reciprocal of the cosine of the angle, that is:
Answer:
138 meters
Step-by-step explanation:
step 1
Find the radius of the circular city plaza
The area is equal to
we have
substitute
solve for r
step 2
we know that
To find out how long is the row of bricks, determine the circumference of the circular city plaza
The circumference is equal to
we have
substitute