The volume of a spherical balloon being inflated changes at a constant rate. If initially its radius is 3 units and after 3 seconds it is 6 units. Find the radius of the balloon after t seconds.

Let the rate of change of the volume of the balloon be k (where k is constant)


Find: Find the radius of the balloon after t second.


=


=


=


=


Integrating both sides, we get:


=


=


= .....(i)


Now, at t = 0, r = 3.


=


=


= C = 36


At t = 3, r = 6:


=


=


=


= k = 84π


Substitute the value of K and C in equation (1), we get


=


=


= r3 = 63t + 27


= r = (63t + 27)1/3


Hence, the radius of the balloon after t seconds is (63 t + 27)1/3 .


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