A6.5-cm-diameter ball has a terminal speed of 18 m/s. what is the ball's mass? use 1.2 kg/m3 for the density of air at room temperature.

Ball's mass is 0.30 kg.

Given :

Diameter = 6.5 cm

Terminal Speed = 18 m/sec

Density of air at room temperature,

Solution :

We know that terminal velocity is given by

So,

 ------ (1)

Where, m is the mass, A is the area and is the drag coefficient.

Now, consider the ball as a perfect sphere therefore,

Now area is,

Now putting the values in equation (1) we get,

m = 0.30 kg

Ball's mass is 0.30 kg.

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