Free fall kinematics under gravity

Steps:

• Initial velocity u = 0 m/s (dropped, not thrown).
• Use equation: v² = u² + 2as, where s = 2 m, a = 10 m/s².
• Substitute: v² = 0 + 2(10)(2) = 40.
• v = √40 ≈ 6.3 m/s.

Why B is correct:

• Matches v = √(2gh) from energy conservation or kinematics, with g=10 m/s² and h=2 m.

Why the others are wrong:

• A: Underestimates speed; √(2100.25)=5 m/s for 0.25 m height.
• C: Equals 2as without square root.
• D: Equals 2as*10, arbitrary multiple.

Final answer: B