SOLUTION: Hi, could you perhaps shed some light on this problem? "Sky divers are in free fall from the time they jump out of a plane until they open their parachutes. A sky diver jumps from
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Question 711321: Hi, could you perhaps shed some light on this problem? "Sky divers are in free fall from the time they jump out of a plane until they open their parachutes. A sky diver jumps from 5000 feet. The diver's height 'h' above the ground 't' seconds after the jump is described by the equation 'h=-16t^2 (squared)+ 5000.' Find the time during which the diver is in free fall assuming that the parachute opens at 1000 feet." Where did the -16t^2 come from? and where does the 1000ft distance come in? Any help would be greatly appreciated!
You can put this solution on YOUR website! Sky divers are in free fall from the time they jump out of a plane until they open their parachutes.
A sky diver jumps from 5000 feet.
The diver's height 'h' above the ground 't' seconds after the jump is described by the equation 'h=-16t^2 (squared)+ 5000.'
Find the time during which the diver is in free fall assuming that the parachute opens at 1000 feet."
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-16t^2 represents the average downward attraction to the earth by gravity
:
You start at 5000 ft, you want the free fall to end at 1000 ft (parachute opens)
therefore h(t) = 1000, find how many seconds for this to happen
:
-16t^2 + 5000 = 1000
subtract 5000 from both sides
-16t^2 = 1000 - 5000
-16t^2 = -4000
t has to be positive, multiply both sides by -1
16t^2 = 4000
divide both sides by 16
t^2 = 250
find the square root of both sides
t =
t = 15.811 seconds to fall to 1000 ft
