Terminal velocity as constant speed on graph Steps:

• Terminal velocity is reached when drag equals weight, causing zero acceleration and constant speed.
• On a speed-time graph, this shows as a horizontal line segment.
• Skydiver accelerates initially, reaches first terminal velocity after spreading limbs, then decelerates upon parachute opening to a lower terminal velocity.
• The final horizontal line after parachute indicates the new terminal velocity.

Why D is correct:

• D is the horizontal line after parachute deployment, where increased drag balances weight for constant lower speed (Newton's first law: net force zero).

Why the others are wrong:

• A: Steep upward slope shows initial acceleration due to gravity exceeding drag.
• B: Horizontal line before parachute shows first (higher) terminal velocity, not after opening.
• C: Downward slope shows deceleration from excess drag after parachute.

Final answer: D