The inner diameter of a circular well is 3.5m .It is 10m deep (a) find the inner curved surface area (b)the cost of plastering the curved surface at the rate of 40/-per m^2
area=depth*PI*2r
cost=cost/m^2 * area
To find the inner curved surface area of the circular well, we need to calculate the circumference and multiply it by the depth.
(a) inner curved surface area:
Step 1: Calculate the radius of the well.
The diameter is given as 3.5m, so the radius (r) can be calculated by dividing the diameter by 2.
r = 3.5m / 2 = 1.75m
Step 2: Calculate the circumference of the well.
The formula for the circumference of a circle is: C = 2πr, where π is a mathematical constant (approximately 3.14).
C = 2π(1.75m) = 2 * 3.14 * 1.75m = 10.99m (approx)
Step 3: Calculate the inner curved surface area of the well.
The formula for the curved surface area of a cylinder is: A = C * h, where C is the circumference and h is the height (or depth in this case).
A = 10.99m * 10m = 109.9m^2 (approx)
Therefore, the inner curved surface area of the circular well is approximately 109.9 square meters.
(b) cost of plastering the curved surface:
To find the cost of plastering the curved surface at the rate of 40/- per square meter, we simply multiply the curved surface area by the cost per square meter.
Step 4: Calculate the cost of plastering.
Cost = Area * Rate
Cost = 109.9m^2 * 40/-
Cost = 4396/-
Therefore, the cost of plastering the curved surface at the rate of 40/- per square meter would be 4396/-.