Answer:
Answer is 17.088 seconds
Step-by-step explanation:
We have given,
Speed of helicopter while going down = 10.5feet/sec
Time taken to travel down = 100 sec
Distance covered while going down = speed * time
Distance covered while going down = 10.5 * 100
Distance covered while going down = 1050 feet
Now,
Speed of helicopter while going up = 5.2feet/sec
time taken to travel up = 150 sec
Distance covered while going up = 5.2 * 150 = 780 feet
After this 250 second period , the position of helicopter will be:
Position of helicopter = distance covered in downward - distance covered upward
Position of helicopter = 1050 - 780 = 270 feet
That means we need to travel upward a distance of 270 feet at a maximum speed of 15.8feet/sec to reach sea level.
Time taken to reach sea level = distance/ speed = 270/15.8 = 17.088 sec
Hence time taken to reach at sea level with maximum speed is 17.088 seconds.
