Question

The diameter of ball a is twice of that of

b. what will be the ratio of their terminal velocities in water?

Answer 1

As terminal velocity is proportional to (diameter)²i.e. terminal velocity is proportional to(radius)², therefore the ratio of terminal velocities of A and B will be 4 :1.

Answer 2

Given:

Diameter of ball a = 2 × diameter of ball b

To find:

The terminal velocity ratio

Solution:

As we know that for calculating terminal velocity . The terminal velocity is directly proportional to the radius square . Therefore, it can also be concluded that the terminal velocity is directly proportional to the square of diameter.

Now,

$\frac{va}{vb} = \frac{ {diameter \: of \: a}^{2} }{ {diameter \: of \: b}^{2} } = \frac{ {2}^{2} }{ {1}^{2} } = \frac{4}{1}$

Hence the ratio is equal yo 4:1.