Parachute opening marks the start of deceleration from terminal velocity

Steps:

• Examine the graph for initial rapid speed increase due to gravity.
• Identify where speed plateaus at terminal velocity from air resistance.
• Locate the point where speed begins decreasing sharply.
• Confirm this decrease aligns with increased drag from the open parachute.

Why B is correct:

• At B, speed starts dropping from terminal velocity, as Newton's second law shows increased drag force exceeds gravitational force, causing net deceleration.

Why the others are wrong:

• A: Speed is still accelerating toward terminal velocity, before sufficient drag buildup.
• C: Speed is already decreasing, post-opening effect.
• D: Speed has stabilized at new lower terminal velocity after opening.

Final answer: B