Answer:
The line of sight distance is 1285.58 feet.
Step-by-step explanation:
The situation is illustrated in the figure attached.
From the figure we see that the altitude difference of the planes and the distance between them form a right triangle with one angle of 40° .
The line of sight between the two planes is the hypotenuse of the triangle.
The altitude difference of the planes is
Therefore, if we call 
the line of sight distance, from trigonometry we have
Therefore, the line of sight distance (x) is 1285.58 feet.
Answer:
okay ill try
Step-by-step explanation:
If the answer correct give me brainliest ok hehehe :p
So this is not too hard, as with any math problem we write what we know.
Starting speed: 80km/h
Time from P to Q: 2.5h
Increase in speed: 20km/h (25% is dividing by 4)
Distance from Q to R: 150 kilometers
So let's find the speed and distance for both legs of the trip.
Speed for P to Q: 80km/h
Distance from PtoQ: 200km (2.5h * 80km/h)
Speed from Q to R: 100km/h (80 +20)
Distance from QtoR: 150km.
Now we multiply the speeds by their respective distances add them and then divide by the total distance.
((80 *200) + (100 * 150))/350 = ~88.57143
