In an experiment to verify Stokes law, a small spherical ball of radius r and density falls under gravity through a distance h in the air before entering a tank of water. If the terminal velocity of the ball inside water is the same as its velocity just before entering the water surface, then the value of h is proportional to (ignore viscosity of air)
Explanation for correct option:
Option (a)
Step 1: Given data
Radius of the ball
Density of the ball is .
Distance between the initial height of ball and water
Step 2: Formula used
Terminal velocity: Terminal velocity is the maximum velocity (speed) attainable by an object as it falls through a fluid.
terminal velocity
mass of the falling object
acceleration due to gravity
density of the fluid through which the object is
projected area of the object
Step 3: Find value of
by the comparing the formula mentioned above and velocity according to the laws of motion, we get:
Hence option (a) is correct.