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Water in a conical tank |
2007-09-10 |
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From Greg:
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?
Answered by Harley Weston. |
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Two inches of topsoil |
2007-09-10 |
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From Nick:
I have to cover a 5,300 square feet area with topsoil 2" deep. How many yards would I need?
Answered by Harley Weston. |
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The elevation of the sun |
2007-09-10 |
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From Elena:
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.
Answered by Harley Weston. |
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Does every number have a square root? |
2007-09-10 |
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From Cheryl:
Does every number have a square root?
Answered by Harley Weston. |
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Segments on a line |
2007-09-10 |
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From Cathy:
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.
Answered by Penny Nom. |
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Binary words |
2007-09-09 |
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From Jan:
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.
Answered by Penny Nom. |
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24 * 1/6 |
2007-09-09 |
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From Laurie:
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.
Answered by Penny Nom. |
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The nth term |
2007-09-09 |
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From Conor:
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...
Answered by Penny Nom. |
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Find All 24 Factors Of 360 |
2007-09-08 |
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From Jennifer:
Find All 24 Factors Of 360
Answered by Penny Nom. |
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Divide a circle into 5 equal parts |
2007-09-07 |
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From Kathy:
How do you divide a circle into 5 equal parts using a protractor?
Answered by Penny Nom. |
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nth term in this series |
2007-09-07 |
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From danii:
im trying to solve the nth term for this pattern.
1 3 6 10 15 21 28
any help would be appretiated
Answered by Stephen la Rocque. |
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The next term |
2007-09-07 |
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From Ariel:
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
Answered by Stephen la Rocque. |
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Markup to include 6% commission |
2007-09-07 |
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From Steve:
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.
Answered by Penny Nom. |
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A parabola with vertex (-1,1) |
2007-09-07 |
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From Ronaldinho:
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!
Answered by Stephen La Rocque and Penny Nom. |
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Dividing a pizza |
2007-09-07 |
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From maryjane:
how do you divide a pizza into eight parts using only three cuts?
Answered by Chris Fisher and Stephen La Rocque. |
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