Answer:
The beam of light is moving at the peed of:
km/min
Given:
Distance from the isalnd, d = 3 km
No. of revolutions per minute, n = 4
Solution:
Angular velocity,
(1)
Now, in the right angle in the given fig.:

Now, differentiating both the sides w.r.t t:

Applying chain rule:


Now, using
and y = 1 in the above eqn, we get:

Also, using eqn (1),


Before we answer this question, let us first understand
what alternate hypothesis is.
The alternative hypothesis is the hypothesis which is
used in the hypothesis testing and this is opposite to the null hypothesis.
This is the test hypothesis which is usually taken to be that the observations
are the result of a real effect in an experiment.
In this case since what we want to set up is the
statistical test to see if the waves are dying down, then this means we are
trying to determine if the wave height are decreasing, so lesser than 16.4
feet. Therefore:
The alternative hypothesis would state (ANSWER)
Ha: μ less than 16.4 feet and
P-value area is on the left of the mean.
While the null hypothesis is the opposite and would state
H0: mu equals 16.4 feet
The speed and distances are directly proportional. Use ratios to solve for vertical y-distance. The ratio of x-distance west to y-distance north equals the x-velocity to y-velocity.
x/y = vx/vy
41/y = 8.6/5.2
41/y = 1.65
41/1.65 = y
24.8 m = y