The radius of a sphere is decreasing at the rate of 3 cm per second. Obtain the rate of decrease of the surface area when the radius is 18 cm.

f the radius of a circle increases at a constant rate 1/(2pi) unit per second, then find the rate of increase of its area, when the radius is 1 unit.

The side of a square is increasing at the rate of 0.01 cm per sec. Find the rate of change of its area at the instant when each side is 4 cms.

The radius of an air bubble is increasing at the rate of 1/2 cm/s. At what rate is the volume of bubble increasing when the radius is 1 cm?

The side of a cube is increasing at the rate of 0.02 cm per sec. Find the rate at which its surface area is increasing when its sides are 3 cms each.

Find the radius of the sphere, if the rates of increase in its volume and surface area are equal.

If the radius of a circle is increasing at the rate of 0.7 cm/s, at what rate is its perimeter increasing?

Find the volume and the surface area of a sphere of radius 5.6 cm.

The sides of an equilateral triangle increae at the rate of sqrt3 cm//sec . What will be the rate of increae in area of the triangle when the length of a side is 5 cm?

At a certain instant the volume of a sphere increses at the rate of 36 cm^3//sec and its surface area increases at the rate of 12 cm^2//sec . find the rate of change of its radius at that instant.