Find the area enclosed between two concentric circles, Mathematics

Assignment Help:

Find the area enclosed between two concentric circles of radii 3.5cm, 7cm. A third  concentric circle is drawn outside the 7cm circle so that the area enclosed between it and the 7cm circle is same as that between two inner circles. Find the radius of the third circle                                                                                                             (Ans: 115.5 cm 2   r = √343 / 2 )

757_circle14.png

Ans:    Area between first two circles = Π x 72 - Π x 3.52

= 49 Π - 12.25 Π -------------(1)

Area between next two circles = Π r2 - Π x 72

= Π r2 - 49 Π -----------------(2)

(1) & (2) are equal

49 Π - 12.25 Π = Π r2 - 49 Π

Π r2 = 49 Π + 49 Π - 12.25 Π

∴ r2 = 98 - 12.25 = 85.75

r2 = 8575/100 = 343/4

r =  √343/2 cm.


Related Discussions:- Find the area enclosed between two concentric circles

Dropped down the rational expression to lowest terms, Carry out the indicat...

Carry out the indicated operation and dropped down the answer to lowest terms.  (x 2 - 5x -14/ x 2 -3x+2) .   (x 2 - 4)/x 2 -14x+49) Solution This is a multiplication.

Describe subtracting negative fractions, Describe Subtracting Negative Frac...

Describe Subtracting Negative Fractions? Subtracting two fractions, whether one is positive and one is negative, or whether they are both negative, is almost the same process a

Tangent, A tangent to a curve at a point is a straight line which tou...

A tangent to a curve at a point is a straight line which touches but does not intersect the curve at that point. A slope of the curve at a point is defined as the

Reduced Row-Echelon Form, The augmented matrix from a system of linear equa...

The augmented matrix from a system of linear equations has the following  reduced row-echelon form (a)  How many equations are there in the system?  (b)  How many variab

George worked from 7:00 am to 3:30 pm how much he earn, George worked from ...

George worked from 7:00 A.M. to 3:30 P.M. with a 45-minute break. If George earns $10.50 per hour and does not obtain paid for his breaks, how much will he earn? (Round to the near

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd