Number 15 is 80 i dont know about the others...sorry
First we convert it in seconds.
Number of seconds in 1 minute = 60 seconds
Therefore,
Number of seconds in 4.2 minutes = 4.2 x 60 = 252 seconds.
Next we convert it in hours.
60 minutes make up an hour. So we can write,
Number of hours in 60 minutes = 1 hour
Number of hours in 1 minute = 1/60 hour
Number of hours in 4.2 minutes = 1/60 x 4.2 = 0.07 hour
Therefore, the video is 252 seconds or 0.07 hour long.
You practically answered this one yourself by giving some of the equation we need already filled in. It would look like this: A(t)=500(1.04)^7. Start by taking 1.04 to the power of 7 to get A(t)=500(1.3159). Finish by multiplying to get
A(t)=$657.97
325 meters if using full height of 324 meters for tower
277 meters if using observation platform height of 276 meters.
When the depression is 37 degrees, you can create a right triangle with the angles 90, 37, and 53 degrees. The distance from a point directly underneath the observer will be:
h/tan(37)
where
h = height of the observer.
And when the depression is 72 degrees, the distance will be:
h/tan(72)
So the distance between the two points will be the absolute value of:
h/tan(72) - h/tan(37)
=(tan(37)h)/tan(37)tan(72) - tan(72)h/(tan(37)tan(72))
=(tan(37)h - tan(72)h) /(tan(37)tan(72))
=h(0.75355405 - 3.077683537)/(0.75355405 * 3.077683537)
=h(0.75355405 - 3.077683537)/(0.75355405 * 3.077683537)
=h(-2.324129487/2.319200894)
=h*-1.002125125
And since we're looking for absolute value
=h*1.002125125
As for the value of "h" to use, that's unspecified in the problem. If you take h
to be the height of the Eiffel Tower, then it's 324 meters. If you take h to be
the highest observation platform on the Eiffel Tower, then it's 276 meters. In
any case, simply multiply h by the value calculated above:
=h*1.002125125
=324*1.002125125
= 324.6885406 m
=h*1.002125125
=276*1.002125125
=276.5865346