Terminal velocity implies constant speed due to balanced forces

Steps:

• Terminal velocity occurs when drag force equals gravitational force, resulting in zero net force.
• Zero net force means zero acceleration, so velocity remains constant.
• If X is time and Y is velocity, the graph shows a horizontal line.
• If X is time and Y is displacement, the graph shows a straight line with constant slope.

Why B is correct:

• Option B depicts a horizontal line for velocity vs. time, matching constant speed at terminal velocity per Newton's first law.

Why the others are wrong:

• A shows increasing velocity, implying acceleration, which occurs before terminal velocity.
• C shows decreasing velocity, contradicting the upward drag balance.
• D shows a curve or oscillation, not possible with balanced constant forces.

Final answer: B