MHT CET202618 April 2026Morning ShiftPhysicsMechanical Properties of FluidsActual
A spherical object is falling under gravity through a viscous fluid. The sphere attains the terminal velocity when
Options
- Aviscous force is zero.
- Bbuoyant force is equal to force due to gravity
- Cviscous force plus force of gravity becomes equal to buoyant force.
- Dbuoyant force plus viscous force becomes equal to force due to gravity.
Correct answer
D. buoyant force plus viscous force becomes equal to force due to gravity.
Step-by-step solution
When a spherical object falls under gravity through a viscous fluid, three forces act on it: 1. Force due to gravity (weight) acting vertically downwards. 2. Buoyant force acting vertically upwards. 3. Viscous drag force acting vertically upwards (opposite to the direction of motion). The object attains terminal velocity when its acceleration becomes zero, meaning the net force acting on it is zero. For the net force to be zero, the total upward force must be equal to the total downward force. Therefore, buoyant fo