SOLUTION: Please help me with the word problem below: Sue likes to walk in the desert. She walks at 2 miles per hour in the desert, and at 4 miles per hour on roads. She wants to get to t

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Question 965649: Please help me with the word problem below:
Sue likes to walk in the desert. She walks at 2 miles per hour in the desert, and at 4 miles per hour on roads. She wants to get to the parking lat as quickly as possible when she is 1 mile from the road and the pakring lot is 2 miles down the road. Rather then walking straight toward her car, or straight toward the road, she will walk at an angle toward the road so she can spend more time walking on the road which is faster. Where should she aim to get to her car the quickest?
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
She walks at 2 miles per hour in the desert, and at 4 miles per hour on roads.
She wants to get to the parking lat as quickly as possible when she is 1 mile from the road and the parking lot is 2 miles down the road.
Rather then walking straight toward her car, or straight toward the road, she will walk at an angle toward the road so she can spend more time walking on the road which is faster.
Where should she aim to get to her car the quickest?
:
Sue
|
|
|
1mi
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|
---(2-x)----*-------x---------Car
:
* is the spot where she enters the road
x = distance walked on the road
let h = hypotenuse, Sue to *, distance walked on the sand
:
h =
h =
h = , the distance walked on the sand
Write a time equation; time = distance/speed
total time = road time + sand time
t = +
plot this on your graphing calc

Time on the vertical axis, distance on the road, on the horizontal (x)
Minimum time occurs when x=1.423 mi from the car, point * she should be walking towards on the sand