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eddy2017

eddy2017

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Oct 27, 2017
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Hi, dear professors:
Lee drove from Swanson to Dennison in 3 hours without stopping. His driving speed varied from 40 miles per hour to 60 mph. lee then drove from Dennison to Westport in 1 hour without stopping. His speed on this part of the trip varied from 20mph to 40 mph. What is the reasonable estimate of the total number of miles that lee drove from Swanson to Westport?.
Given
from Swanson to Dennison in 3 hours. No stopping.
his driving speed varied from 40 miles per hour to 60 mph.
from Dennison to Westport in 1 hour without stopping.
His speed on this part of the trip varied from 20mph to 40 mph
What is the reasonable estimate of the total number of miles that lee drove from Swanson to Westport=?
I need a hint to get started.
Thanks in advance,
eddy
 
eddy2017 said:
Hi, dear professors:
Lee drove from Swanson to Dennison in 3 hours without stopping. His driving speed varied from 40 miles per hour to 60 mph. lee then drove from Dennison to Westport in 1 hour without stopping. His speed on this part of the trip varied from 20mph to 40 mph. What is the reasonable estimate of the total number of miles that lee drove from Swanson to Westport?.
Given
from Swanson to Dennison in 3 hours. No stopping.
his driving speed varied from 40 miles per hour to 60 mph.
from Dennison to Westport in 1 hour without stopping.
His speed on this part of the trip varied from 20mph to 40 mph
What is the reasonable estimate of the total number of miles that lee drove from Swanson to Westport=?
I need a hint to get started.
Thanks in advance,
eddy
Click to expand...
Start from the question, write down the expression that answers it using variables. If some of the variables are not yet known, write down the expressions for those variables. Continue until you run out of data from the problem. Calculate all expressions or solve equations.
 
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If all you know is that Lee varied his speed from 40 mph to 60 mph, then how far do you think Lee drove for the 1st 3 hours. What is a reasonable guess?
 
lev888 said:
Start from the question, write down the expression that answer it using variables. If some of the variables are not yet known, write down the expressions for those variables. Continue until you run out of data from the problem. Calculate all expressions or solve equations.
Click to expand...
okay, let me work at it. Thanks.
 
Jomo said:
If all you know is that Lee varied his speed from 40 mph to 60 mph, then how far do you think Lee drove for the 1st 3 hours. What is a reasonable guess?
Click to expand...
A reasonable guess would be 2,400 miles. Multiplying 40 * 60 to find that estimate.
 
eddy2017 said:
A reasonable guess would be 2,400 miles. Multiplying 40 * 60 to find that estimate.
Click to expand...
I make many more mistakes then you do but I think about whether my answer make sense. Do you really think that you can drive 2400 miles in three hours and not go over 60mph? If you drive at 60 mph for three hours then how far do you drive?
 
lev888 said:
Start from the question, write down the expression that answers it using variables. If some of the variables are not yet known, write down the expressions for those variables. Continue until you run out of data from the problem. Calculate all expressions or solve equations.
Click to expand...
I know what you want me to do but i am having a hard time figurin' out how to write the variation in speed in math notation.
 
Jomo said:
I make many more mistakes then you do but I think about whether my answer make sense. Do you really think that you can drive 2400 miles in three hours and not go over 60mph? If you drive at 60 mph for three hours then how far do you drive?
Click to expand...
Yes, and that is why i gave the other option which is logical. 150
 
eddy2017 said:
A reasonable guess would be 2,400 miles. Multiplying 40 * 60 to find that estimate.
Click to expand...
Think about what you are saying. Regardless of the number of hours you drive if you drive between 40mph and 60 mph you average about 2400 miles. How can the number of hours not be used in your solution?
 
Jomo said:
Think about what you are saying. Regardless of the number of hours you drive if you drive from 40mph to 60 mph you average about 2400 miles. How can the number of hours not be used in your solution?
Click to expand...
You asked me to make an estimate of the speed. I did. 50 miles. Oh, wrote 150. Sorry. it's 50 miles
average speed 50 miles * 3 h =150 miles
From Dennison to Weston the average is 30 * 1h=30
so 150 + 30 =180 is a reasonable estimate of the total miles that he drove, or so I think.
 
eddy2017 said:
You asked me to make an estimate of the speed. I did. 50 miles. Oh, wrote 150. Sorry. it's 50 miles
average speed 50 miles * 3 h =150 miles
From Dennison to Weston the average is 30 * 1h=30
so 150 + 30 =180 is a reasonable estimate of the total miles that he drove, or so I think.
Click to expand...
i took into account the hours now.
 
You asked me to make an estimate of the speed. I did. 50 miles. Oh, wrote 150. Sorry. it's 50 miles
average speed 50 miles * 3 h =150 miles
From Dennison to Weston the average is 30 * 1h=30

Everything you wrote above is wrong.

Average speed 50miles*3hrs = 150 miles: First average speed is a speed and a speed is distance/time as in miles/hour NOT miles*hrs as you wrote. 50 miles *3 hrs does NOT equal 150 miles. 50 miles * 3 hrs = 150 miles* hrs (whatever that means)

From Dennison to Weston the average is 30 * 1h=30: No, 30*1hr does NOT equal 30. 30 *1 = 30! For the record, 30* 1hr = 30 hrs.
 
Jomo said:
You asked me to make an estimate of the speed. I did. 50 miles. Oh, wrote 150. Sorry. it's 50 miles
average speed 50 miles * 3 h =150 miles
From Dennison to Weston the average is 30 * 1h=30

Everything you wrote above is wrong.

Average speed 50miles*3hrs = 150 miles: First average speed is a speed and a speed is distance/time as in miles/hour NOT miles*hrs as you wrote. 50 miles *3 hrs does NOT equal 150 miles. 50 miles * 3 hrs = 150 miles* hrs (whatever that means)

From Dennison to Weston the average is 30 * 1h=30: No, 30*1hr does NOT equal 30. 30 *1 = 30! For the record, 30* 1hr = 30 hrs.
Click to expand...
How to set up the whole thing so the units can cancel properly leaving only miles?.
Is a proportion a valid thing here?.
 
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Speed = Miles per Hr = Miles/Hrs. You put Miles in the numerator and hrs in the denominator to find speed or rate.

If you drive 25 miles per hour for 4 hours then you drove [math]\dfrac{25 miles}{ hr}*4 hrs[/math]
You seem frustrated that you are not getting the units you want to get.

I am more concerned that you are getting the wrong units and you don't think a moment about it. How can 50miles*3hrs = 150 miles? It is clear that on the left the units are miles*hr and on the right it is miles. They are not the same! So you think where am I making my mistake. You just don't let it go.
 
Distance=Rate*Time.

We assume that you are averaging 50miles/hr for 3 hrs.
Rate = 50miles/hr and Time = 3 hrs.

So Distance = 50miles/hr * 3 hrs = 150 miles. Do you see the hrs cancelling out??
 
Jomo said:
Distance=Rate*Time.

We assume that you are averaging 50miles/hr for 3 hrs.
Rate = 50miles/hr and Time = 3 hrs.

So Distance = 50miles/hr * 3 hrs = 150 miles. Do you see the hrs cancelling out??
Click to expand...
Yes, then,
D= 30 miles/hr * 1hr =30 miles.
Got it!.
then i can add up the two amounts of miles.
150 miles + 30 miles =180. that is the reasonable estimate of the total number of miles that lee drove from Swanson to Westport.
Thanks a lot.
 
eddy2017 said:
I know what you want me to do but i am having a hard time figurin' out how to write the variation in speed in math notation.
Click to expand...
Could you reread this thread?
Notice any similarity with previous threads?
What I noticed: after my repeated suggestions to stop and think about what the question is asking you and starting there, you continue to do random operations with random numbers from the problem. Do you think this approach is useful?
 
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