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Water in a conical tank |
2007-09-10 |
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Greg pose la question :
Joe is conducting an experiment to study the rate of flow of water from a conical tank.
The dimensions of the conical tank are:
Radius at the initial water level = 13.7 cm
Radius at the reference point = 12.8 cm
Initially the tank is full of water. There is a circular orifice at the bottom of the conical
tank with a diameter of 0.635 cm. The water drains from the conical tank into an empty
cylindrical tank lying on its side with a radius of 0.500 ft and a length L (ft).
Joe observed the water discharged with an average velocity of 1.50 m/s as the water level
lowered from the initial height of 14.0 cm to 5.00 cm in the conical tank. Answer the
following:
1. If the initial height of water in the conical tank is 14.0 cm (measured from the
reference point, see Fig. 1), how long in seconds will it take for the water level to drain to
a height of 5.00 cm?? NOTE: Height refers to the vertical height.
What formula would I use to find out how long in seconds it takes for the water level to drop?
Harley Weston lui répond. |
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Two inches of topsoil |
2007-09-10 |
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Nick pose la question :
I have to cover a 5,300 square feet area with topsoil 2" deep. How many yards would I need?
Harley Weston lui répond. |
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The elevation of the sun |
2007-09-10 |
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Elena pose la question :
The "angle of elevation" of an object about you is the angle between a horizontal line of sight between you and the object. (See figure) After the sun rises, its angle of elevation increases rapidly at first, then more slowly, reaching a maximum near noontime. Then the angle decreases until sunset. The next day the phenomenon repeats itself. Assume that when the sun is up, its angle of elevation (E) varies sinusoidally with the time of day. Let t be the number of hours that has elapsed since midnight last night. Assume that the amplitude of this sinsoid is 60 degrees, and the maximum angle of elevation occurs at 12:45 p.m.. Assume that at this time of year the sinusoidal axis is at E=-5 degrees. The period is, of course, 24 hours.
a. Sketch a graph of this function
b. What is the real-world significance of the t - intercepts?
c. What is the real world significance of the portion of the sinusoid, which is below the t-axis?
d. Predict the angle of elevation at 9:27 a.m., and at 2:30 p.m.
e. Predict the time of sunrise
f. As you know, the maximum angle of elevation increases and decreases with the change of the seasons. Also, the times of sunrise and sunset change with the seasons. What one change could you make to your mathematical model that would allow you to use it for predicting the angle of elevation of the sun at time on any day of the year.
Harley Weston lui répond. |
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Does every number have a square root? |
2007-09-10 |
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Cheryl pose la question :
Does every number have a square root?
Harley Weston lui répond. |
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Segments on a line |
2007-09-10 |
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Cathy pose la question :
This question was on my daughter's geometry assignment. Write a general rule of formula for finding the number of segments that can be named by a given number of points on a line. For example, 2 points on a line = 1 line segment; 3 points on a line = 3 segments; 5 points on a line = 10 segments.
Penny Nom lui répond. |
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Binary words |
2007-09-09 |
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Jan pose la question :
A computer word is made of strings of 0's and 1's. How many different words can be formed using 8 characters?
Example is 01010101.
Penny Nom lui répond. |
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24 * 1/6 |
2007-09-09 |
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Laurie pose la question :
24 * 1/6
I don't no where the 24 goes and if the number must be the same to devide
into the numerator and the denominator .
Thankyou for your time.
Penny Nom lui répond. |
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The nth term |
2007-09-09 |
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Conor pose la question :
Please can you help me with this question on the subject of the Nth term.
3.5, 5, 6.5, 8, 9.5
5.1, 7.2, 9.3, 11.4...
Penny Nom lui répond. |
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Find All 24 Factors Of 360 |
2007-09-08 |
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Jennifer pose la question :
Find All 24 Factors Of 360
Penny Nom lui répond. |
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Divide a circle into 5 equal parts |
2007-09-07 |
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Kathy pose la question :
How do you divide a circle into 5 equal parts using a protractor?
Penny Nom lui répond. |
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nth term in this series |
2007-09-07 |
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danii pose la question :
im trying to solve the nth term for this pattern.
1 3 6 10 15 21 28
any help would be appretiated
Stephen la Rocque lui répond. |
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The next term |
2007-09-07 |
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Ariel pose la question :
Please explain to me why -3^2 is a -9. One calculator give me an answer of positive 9.
WHAT IS THE NEXT TERM IN Each sequence/ What is its term number?
1/2, 2/3, 3/4, 5/6 6/7
1, 1/4, 1/9, 1/16
Stephen la Rocque lui répond. |
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Markup to include 6% commission |
2007-09-07 |
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Steve pose la question :
I estimate the cost to build a house for $250,000.00. I mark it up by 20%:
$250,000 x 1.20 = $300,000 base price (BP) without sales commission. I want to set
the sale price (SP) to include a 6% commission to pay the real estate fee. After the
6 % fee is paid I want to net the $300,000 base price. The formula is basically:
$300,000 + 6% of SP = SP. But I can't figure out how to solve for SP.
Penny Nom lui répond. |
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A parabola with vertex (-1,1) |
2007-09-07 |
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Ronaldinho pose la question :
Hello. How do you find the equation of a parabola shown on a graph? i know the vertex is (-1,1) and that's it. Thanks!
Stephen La Rocque and Penny Nom lui répond. |
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Dividing a pizza |
2007-09-07 |
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maryjane pose la question :
how do you divide a pizza into eight parts using only three cuts?
Chris Fisher and Stephen La Rocque lui répond. |
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