What is the radius of two cicles with one radius longer than the other one?
Q. The radius of a circle is 1 meter longer than the radius of another circle. If their areas, differ by 5 (3.14) square meters, then what is the radius of each?
Asked by black pearl - Fri Jan 9 13:04:02 2009 - - 2 Answers - 0 Comments

A. Circle A has a radius of x. Circle B has a radius of x + 1 (1 unit larger than circle A). The equations for the area of each is as follows: Area of A = pi(x^2) Area of B = pi[(x+1)^2] = pi(x^2 + 2x + 1) The difference if the areas between the two circles is known so we can write an equation the solve for x: The difference in area = The area of B - the area of A pi(5) = pi(x^2 + 2x + 1) - pi(x^2) pi(5) = pi[(x^2 + 2x + 1) - (x^2)] Divide both sides by pi and you get: 5 = (x^2 + 2x + 1) - (x^2) = 2x + 1 Solve for x: 2x + 1 = 5 2x = 4 x = 2 By this we know that the radius of Circle A is 2 meters and the radius of Circle B is 3 meters. I hope this helps.
Answered by Jeremy - Fri Jan 9 13:17:55 2009

Why is the radius of a fluoride ion similar to that of a fluorine atom?
Q. Aren't radii of anions larger than their corresponding atoms? Why is the radius of a fluoride ion(0.133 nm) similar to that of a fluorine atom?(that's a question from my textbook) Is there something to do with its electronegativity?
Asked by twister - Mon Dec 1 06:57:13 2008 - - 1 Answers - 0 Comments

A. fluorine ion is larger than the fluorine atom because fluorine ion has a stronger positive charge on its nucleus than fluorine atom.=] hope it will help=]
Answered by scientific - Tue Dec 2 01:51:59 2008

What is the average radius of a roller coaster loop?
Q. Yes, i know roller coaster loops are tear drop shaped so it's hard to say the radius. But I have to design a roller coaster for physics and I was wondering what would be a reasonable radius of the loop?
Asked by Rachael F. - Sun Feb 8 12:35:15 2009 - - 1 Answers - 0 Comments

A. it depends how long the train is minimum 25 feet. maximum depends on speed and weight of train.
Answered by tooosmart2 - Sun Feb 8 12:41:04 2009

How fast is the radius of the wetted area expanding?
Q. Water is falling on a surface, wetting a circular area that is expanding at a rate of 3mm^2/s. How fast is the radius of the wetted area expanding when the radius is 128 mm? Round to four decimals places.
Asked by Panda Tran - Thu Jul 2 15:06:59 2009 - - 1 Answers - 0 Comments

A. A=pi*R^2 dA=2*pi*R*dR 3 mm^2/sec=2*pi*(128 mm)*dR dR=3/(256*pi)=0.003732 mm/sec
Answered by Denis S - Thu Jul 2 15:15:55 2009

What is the radius of a gold atoms nucleus?
Q. I know the radius of a gold atom is 0.1441 nanometers but what is the size of it's nucleus?
Asked by Leah G. K. - Mon Oct 12 18:29:53 2009 - - 1 Answers - 0 Comments

A. look it up
Answered by caroline m - Mon Oct 12 18:33:13 2009

How to find the radius from the total volume and height?
Q. I need some help with homework. I've been given 47 as the total volume and 3 as the radius. How do I find the height? The shape is a cone.
Asked by kasumi_satoshi - Tue Jan 9 17:26:22 2007 - - 1 Answers - 0 Comments

A. The formula is V = 1/3 * * r^2 * h So 47 = 3^2 * * h / 3 47 = 3 * h h = 47 / (3 ) which is about 4.98685488
Answered by Nature Nate - Tue Jan 9 17:34:41 2007

How can I find the radius of a cylinder when I am given the height and volume?
Q. The height of my cylinder is 25 ft and the volume is 935 ft^3. How do I go about finding the radius of this cylinder?
Asked by Stephanie S - Mon Feb 11 22:01:59 2008 - - 5 Answers - 0 Comments

A. the volume is V=pi r^2 h divide both sides by pih V/pih=r^2 take the square root of both sides to get only r r=square root of (V/pih) r=square root of 935/pi25 r=3.45
Answered by newtonnana - Mon Feb 11 22:13:11 2008

How can you find the radius from knowing the circumference of a circle?
Q. Okay, I am having a little trouble in math, And forgot to bring my textbook home. So The question is: The circumference of a circle is 56cm. What is the radius of the circle? If you could just show me the formulas or how to do the question, I'd be GREAT! Thanks again, Katie J.
Asked by Katie J - Sun Nov 16 19:03:29 2008 - - 5 Answers - 0 Comments

A. The first answerer gave you Pi r squared, which is to find the AREA of the circle. the 2pi(r) is the correct formula.
Answered by Novafury - Wed Nov 19 23:29:57 2008

What is the radius of the circle circumscribing the pentagon in a five sided star?
Q. Here' s an imperfect picture of what I mean (drawn in Paint) I want to find the radius of the circle circumscribing the pentagon in the star (the length of the red line). The radius of the larger circle is known.
Asked by S - Sun Apr 6 18:05:13 2008 - - 1 Answers - 0 Comments

A. OK -- draw yourself a nice picture and give it some labels. This is going to be a little wild. (There may be another way that's a little more suave, but we're going to try it this way right now . . .) Orient your star so that there is a point of the star at the top of the diagram. Label this top point "A." Label the other four points of the star in a clockwise fashion -- "B," "C," "D," and "E." Now -- draw a vertical line from "A", through the center of the circle, until it hits the bottom of the circle. Label the point where this line intersects the bottom of the circle "F." Label the point where this line intersects the bottom, concave part of the star "G." Next -- connect points "C" and "F" with another line. Now it's time to… [cont.]
Answered by Answer Guy - Sun Apr 6 21:28:30 2008

What is the ratio of the radius of a circle to the side of a pentagon that can be made inside the circle?
Q. In other words, what do I multiply the radius by to find a segment that is one fifth of the circle?
Asked by jurassicbeaver - Thu Jul 2 11:31:50 2009 - - 2 Answers - 0 Comments

A. Assuming the pentagon is a regular pentagon, the two shapes share the same center. If we call the distance from the pentagon's center to one of its corners R, then using some trigonometry, we can find the length of the side in terms of R. Here's a picture of an inscribed pentagon to help you: If we draw R, the line from the center to the vertex, and the apothem, which is the perpendicular bisector of the polygon's side ( we get a right triangle whose sides are R, the radius, A, the apothem, and 1/2 S, half of the side. We know the angles of a regular pentagon measure 108 degrees. Since we have only half of the angle, that angle measures 54 degrees (this is the angle between R and 1/2 S). Using some trig: cos 54 = (1/2 S)/R 1/2 S… [cont.]
Answered by Some Body - Thu Jul 2 11:48:00 2009

How to find the radius of a sphere inscribed in a cone ?
Q. When all you know is the radius and height of the cone ? help me please! Radius is 7, height is 24 .
Asked by gutta - Tue Feb 24 11:26:55 2009 - - 2 Answers - 0 Comments

A. Well, draw the cone as seen from the front - it's a triangle, then calculate the center of the circle inscribed in it - the intersection of the angle bisectors, then measure the length from the center to any of the sides of the triangles, that is your radius.
Answered by taurenthew - Tue Feb 24 11:37:46 2009

what is the turn radius of a jetline?
Q. I want to know what the average turn radius for a small jet liner aircraft while in the air coming to land, also how far out they line up from the airport. I have a cabin in michigan in proximity to an airport and although planes fly over i dont believe they are going to that airport because the angle at which they fly, so ive used google earth and AutoCAD to calculate the minimum turn radius for a plane to land safely on the runway but cannot find if an aircraft is capable of making the turn. Any help would be appreciated.
Asked by bigalexe - Fri Jan 26 13:04:15 2007 - - 3 Answers - 0 Comments

A. I am an airline transport pilot and a retired chair of a university airway science dept. - the turn radius varies (don't you love that?). In general, a plane coming in to land, at an approach speed, turns at a bank angle of 15-20 degrees, and is flying in the vicinity of 150-170 mph. If the airport in question has a control tower, there is usually a published approach that the planes will follow, which may not look like a "normal" approach. Additionally, the aircraft controllers have several options for directing traffic based on weather conditions and/or congestion. You can go to pretty much any local airport and purchase a booklet of "approach plates" which would have the recommended approach to the airport in question IF it has a… [cont.]
Answered by decivilian - Fri Jan 26 13:21:10 2007

How do i find gravity given a radius and an altitude?
Q. Using g = m/r^2? What is the acceleration due to gravity at an altitude of 1.00 x 10^6 above the earth's surface, given that the radius of the earth is 6.38 x 10^6 m? How do i go about solving that?
Asked by Voldemort - Thu Dec 20 21:07:38 2007 - - 2 Answers - 1 Comments

A. Let's try this: First: Fg = GMm/r^2 So, if you are only changing r then write Fg1 = GMm/r1^2. Now write Fg1 / Fg2 = GMm/r1^2 divided by GMm/r2^2 Canceling gives Fg1 / Fg2 = r2^2/r1^2 Um ... you can do the same thing with g, since g = Fg/m .: g1/g2 = r2^2/r1^2 (you can work it out using the same procedure as in the previous paragraph. Maybe I should just have started with this, but I am figuring it out as I type). Since you know g1 = 9.81/m/s/s and r1=6.38E6 and r2=1.00E6 + r1 (you MUST add the earth's radius to the altitude. ALWAYS do this anytime you see the code word ALTITUDE), you know all of the variables in the equation except for g2 --- which is what you are trying to find.
Answered by mk_gecko - Thu Dec 20 21:23:21 2007

What is the velocity of the water in the 5 cm radius tube?
Q. A tube of radius 5 cm is connected to tube of radius 1 cm as shown above. Water is forced through the tube at a rate of 10 liters/min. The pressure in the 5 cm tube is 1 105 Pa. The density of water is 1000 kg/m3. Assume that the water is nonviscous and uncompressible.
Asked by svucich2 - Mon Apr 7 14:17:55 2008 - - 1 Answers - 0 Comments

A. First of all, there is no figure "shown above" in your post. Anyway, in any closed system, Flow rate = Q = AV where A = cross-sectional area of a tube V = fluid velocity From the given of your problem, 10 liters/min = (pi)(5)^2(V) There are 1000 cc per liter, so (10)(1000) = 25(pi)V^2 V^2 = 10,000/(25 * pi) V^2 = 127.32 V = 11.28 cm/min.
Answered by Pointy - Mon Apr 7 14:45:41 2008

How do I calculate the angle of a wheel for a turning radius?
Q. I am a 3d modeler and made an audi a8 model. I want to be accurate with the turning radius and I need to know what angle I need the wheels to be in order to reach the A8's turning radius of 6.15m.
Asked by knirb01 - Sun Jul 26 10:15:09 2009 - - 2 Answers - 0 Comments

A. It depends which turning radius you are referring to. The turning radius of the front wheels is different to the back wheels - which are smaller than that at the front. Also when you are talking about radius you need to be sure where this is measured from. From the centre line of the car or from the wheel inside of the turn. Length of car: L (distance between front and back axes!) Angle in degrees. Measured from the directional sense of the car. So 0 is when car drives straight. Angle of front wheel with back centre-axle of turning radius r. Note that radius r is measured from the *centre line* (symmetry line) of the car length. So you need to add/subtract accordingly depending what you need. eg, if radius 6.15 measured from wheels,… [cont.]
Answered by wgh - Sun Jul 26 11:08:07 2009

What is the relationship between melting points and atomic radius?
Q. Also what is atomic radius? I have also got to explain why there is 'this' pattern in melting points? Anyone help me at all? I'm a bit confused
Asked by Caz - Sat Oct 17 08:49:47 2009 - - 2 Answers - 0 Comments

A. atomic radius is the mean distance between the nucleus and the outermost electron cloud. in the periodic table,it is observed that as the atomic radii increases, the melting point decreases. in a group, the melting point increases as we proceed downwards.this is becoz the valence electrons are present far away from the electrons and hence requires less energy to breakup the lattice. in a period a we go from left to right the atomic radius decreases and hence the MP increases
Answered by studious - Sat Oct 17 09:10:10 2009

What is the radius of curvature and how far in front must it be located?
Q. The image of a smiley face is to be formed on a screen 5 m from a concave mirror. The smiley face is 5 mm long and the image is to be 50 cm long. 1.) What is the radius of curvature of the mirror? 2.) HOw far in front of the vertex of the mirror should the smiley face be located? Provide me some equations/explantations you used to solve the equation. Thanks.
Asked by Veteran Ace - Sun May 10 12:53:44 2009 - - 1 Answers - 0 Comments

A. 1/f = 1/o + 1/i i/o = 500/5 o = i/100 1/f = 1/(i/100) + 1/i 1/f = 100/i + 1/i 1/f = 101/i f = i/101 f = 5/101 m 1) r = 2f r = 2*5/101 r = 10/101 m 2) o = i/100 o = 5/100 o = 0.05 m o = 5 cm
Answered by sweetwater - Wed May 13 03:04:48 2009

How do you find radius when given volume for a sphere?
Q. How do you find radius when given volume for a sphere?
Asked by ZVXO - Thu Sep 10 20:07:04 2009 - - 12 Answers - 0 Comments

A. The volume of a sphere is (4/3) * pi * (r^3), where r is the radius. So if you are given volume (v) you can reverse the formula. v = (4/3) * pi * (r^3) v * (3/4) = pi * (r^3) (v / pi) * (3/4) = r^3 take the cube root of both sides, and you'll have r. ~ Megan
Answered by unknown - Thu Sep 10 20:12:20 2009

What is the effect on the volume of a right cylinder if its radius is tripled?
Q. Ok so there's the question: What is the effect on the volume of a right cylinder if its radius is tripled? 10 points for best answer! I'M desperate please! :] What is the effect on the volume of a right cylinder if its radius is tripled?
Asked by ~ily~ - Mon Feb 2 22:47:17 2009 - - 1 Answers - 0 Comments

A. To calculate the volume you multiply the Base by the Height. Say the radius is 5cm and the height is 20cm 5x20 = 100cm cubed However if the radius is tripled it would become 15cm so change the equation to 15x20 = 300 cm cubed
Answered by Nick M - Mon Feb 2 23:01:13 2009

What is the shwarzschild radius of a tennis ball?
Q. If the tennis ball is 6.5 cm in diameter , it's mass is 57 grams. --- does every mass has a "shwarzschild radius"?
Asked by marwa i - Thu May 21 10:17:59 2009 - - 1 Answers - 0 Comments

A. Theoretically, yes, but the S.R. of a tennis ball would be so incredibly small as to be nonexistent. If the Shwarzschild Radius were the SIZE of a tennis ball, you'd lose half the state!
Answered by Tom E - Thu May 21 10:26:16 2009