Question

A solid sphere falls with a terminal velocity of 20 m s^-1 in air. If it is allowed to fall in vacuum,

• A. Terminal velocity will be 20 ms^-1
• B. Terminal velocity will be less than 20 m s^-1
• C. Terminal velocity will be more than 20 m s^-1
• D. There will be no terminal velocity

Answer 1

The correct option is D

There will be no terminal velocity

As there is a viscous force acting on the object (due to friction), because of the presence of surrounding medium, it attains a uniform velocity after sometime.

But if there is no medium to resist the motion of the object, it will continuously increase its velocity and terminal velocity will never be attained.

Hence (d).