Pressure determines nail penetration depth

Steps:

• Identify that both nails experience the same force into identical wood.
• Recall pressure formula: P = F/A, where smaller area A increases P for fixed F.
• Assume Nail X has smaller cross-sectional area than Y, leading to higher pressure for X.
• Conclude X penetrates deeper due to concentrated force.

Why A is correct:

• A states X penetrates deeper, per pressure law (P = F/A), as smaller area amplifies penetration.

Why the others are wrong:

• B incorrectly claims Y penetrates deeper, ignoring area difference.
• C wrongly suggests equal penetration, overlooking pressure variation.
• D mistakenly implies no penetration difference, violating force distribution principle.

Final answer: A