SOLUTION: Jan rollerskated to Cindy’s house against a strong headwind. She got there in 20 minutes. When she went back home, the tail wind strength was the same as before. That trip took onl
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-> SOLUTION: Jan rollerskated to Cindy’s house against a strong headwind. She got there in 20 minutes. When she went back home, the tail wind strength was the same as before. That trip took onl
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Question 259924: Jan rollerskated to Cindy’s house against a strong headwind. She got there in 20 minutes. When she went back home, the tail wind strength was the same as before. That trip took only 8 minutes. How long would it take Jan to ride to her Cindy’s house if there was no wind? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Jan rollerskated to Cindy’s house against a strong headwind.
She got there in 20 minutes.
When she went back home, the tail wind strength was the same as before.
That trip took only 8 minutes.
How long would it take Jan to ride to her Cindy’s house if there was no wind?
:
Let s = her speed with no wind
Let w = the force of the wind
then
(s-w) = her speed against the wind
and
(s+w) = her speed with the wind
:
Choose a convenient number for the distance, 40 units
:
write two distance equations, time * speed = distance
20(s-w) = 40
8(s+w) = 40
Simplify, divide the 1st equation by 20, the 2nd equation by 8
s - w = 2
s + w = 5
----------addition eliminates w
2s = 7
s = 7/2
s = 3.5
:
Find the time at this speed: = 11.43 min with no wind
;
:
Prove this find the times of each situation
When her speed is 3.5 the wind = 1.5
:
against: 40/(3.5-1.5) = 20 min
with: 40/(3.5+1.5) = 8 min
