A spherical ball of salt is dissolving in water in such a manner that the rate of decrease of volume at any instant is proportional to the surface. Prove that the radius is decreasing at a constant rate.

A spherical balloon is being inflated so that its volume increase uniformaly at the rate of 40 cm^(3)//"minute" . The rate of increase in its surface area when the radius is 8 cm, is

If the volume of a sphere is increasing at a constant rate, then the rate at which its radius is increasing, is

A growing raindrop. Suppose that a drop of mist is a perfect sphere and that, through condensation, the drop picks up moisture at a rate proportional to its surface area. Show that under these circumstances the drop's radius increases at a constant rate.

Suppose that water is emptied from a spherical tank of radius 10 cm. If the depth of the water in the tank is 4 cm and is decreasing at the rate of 2 cm/sec, then the radius of the top surface of water is decreasing at the rate of

The rate of change of surface area of a sphere of radius r when the radius is increasing at the rate of 2 cm/sec is proportional to

A small spherical ball falling under gravity in a viscous medium heat the medium due to viscous drage force. The rate of heating is proportional to r^(n) . ( r= radius of the sphere find ) n .

The radius of spherical bubble is changing with time. The rate of change of its volume is given by :

If the rate of change in volume of spherical soap bubble is uniform then the rate of change of surface area varies as