After terminal velocity is reached the acceleration of a body falling through a viscous fluid is:

Options

A. zero
B. equal to g
C. less than g
D. more than g

Explanation

To solve the question "After terminal velocity is reached, the acceleration of a body falling through a viscous fluid is:", we can follow these steps:

### Step 1: Understand the Forces Acting on the Body
When a body falls through a viscous fluid, two main forces act on it:
- The gravitational force (weight) acting downward.
- The viscous force acting upward, which opposes the motion of the body.

### Step 2: Define Terminal Velocity
Terminal velocity is the constant speed that a freely falling object eventually reaches when the resistance of the medium (in this case, the viscous fluid) prevents further acceleration. At this point, the forces acting on the body are balanced.

### Step 3: Apply Newton's Second Law
According to Newton's second law of motion, the net force acting on an object is equal to the mass of the object multiplied by its acceleration (F_net = m * a).

### Step 4: Analyze the Situation at Terminal Velocity
At terminal velocity:
- The downward gravitational force (weight) is equal to the upward viscous force.
- Therefore, the net force acting on the body is zero.

### Step 5: Conclude About the Acceleration
Since the net force is zero, according to Newton's second law:
- F_net = 0 = m * a
This implies that the acceleration (a) of the body is also zero.

### Final Answer
Thus, after terminal velocity is reached, the acceleration of a body falling through a viscous fluid is **0**.

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