Solution:
Let the radius of the circular wave ring be r cm at any time t.
Then (Given)
Let A be the area of the enclosed ring. Then,
A stone is dropped into a quiet lake. If the waves moves in circles at the rate of 30 cm/sec when the radius is 50 m, the rate of increase of enclosed area, is
Let the radius of the circular wave ring be r cm at any time t.
Then (Given)
Let A be the area of the enclosed ring. Then,