Advertisements
Advertisements
प्रश्न
"Area A oof a circular ring formed by 2 concentric circles is equal to the product of pie and the difference of the square of the bigger radius R and the square of the bigger radius R and the square of the smaller radius r. Express the above statement as a formula. Make r the subject of the formula and find r, when A = 88 sq cm and R = 8cm.
Advertisements
उत्तर
Radius of bigger circle = R
Radius of smaller circle = r
Area = A = π(R2 - r2)
⇒ A = π(R2 - r2)
⇒ `"A"/pi = "R"^2 - "r"^2`
⇒ r2 = `"R"^2 - "A"/pi`
⇒ r = `sqrt("R"^2 - "A"/pi)`
Putting A = 88cm2 and R = 8cm
⇒ r = `sqrt(8^2 - 88/(22/7)`
= 6cm.
APPEARS IN
संबंधित प्रश्न
Make a formula for the statement:"The reciprocal of focal length f is equal to the sum of reciprocals of the object distance u and the image distance v."
Make a formula for the statement:"The number of diagonals, d, that can be drawn from one vertex of an n sided polygon to all the other vertices is equal to the number of sides of the polygon less 3"
Make R the subject of formula A = `"P"(1 + "R"/100)^"N"`
Make a the subject of formula S = `("a"("r"^"n" - 1))/("r" - 1)`
Make a the subject of the formula S = `"n"/(2){2"a" + ("n" - 1)"d"}`. Find a when S = 50, n = 10 and d = 2.
Make m the subject of the formula x = `"my"/(14 - "mt")`. Find m, when x = 6, y = 10 and t = 3.
Make f the subject of the formula D = `sqrt((("f" + "p")/("f" - "p"))`. Find f, when D = 13 and P = 21.
Make c the subject of the formula a = b(1 + ct). Find c, when a = 1100, b = 100 and t = 4.
The pressure P and volume V of a gas are connected by the formula PV = C; where C is a constant. If P = 4 when V = `2(1)/(2)`; find the value of P when V = 4?
The total energy E possess by a body of Mass 'm', moving with a velocity 'v' at a height 'h' is given by: E = `(1)/(2) "m" "u"^2 + "mgh"`. Find m, if v = 2, g = 10, h = 5 and E = 104.
