Question 1
A woman wearing high heels exerts a force of 500 N on the ground. Each heel has a contact area of 0.0001 m². What is the pressure exerted by one heel?No clue? Show me the answer
Correct answer
Correct!
IncorrectStep-by-step walkthrough
Choose a solution method
Method #1Direct ApproachStep 1: Identify the known values
We are given Force N and Area m². We need to find pressure .
Step 2: Apply the pressure formula
Use the formula:
Step 3: Substitute the values
Step 4: State the answer with units
The pressure exerted by one heel is 5,000,000 Pa (5 MPa). This shows why high heels can damage soft floors — enormous pressure on a tiny area!
Method #2Process of EliminationStep 1: Identify what we need
We need with N and m². Let's check each option by working out what area would give that pressure.
Step 2: Eliminate 5,000 Pa
If Pa, then m². That is far larger than m², so 5,000 Pa is too small.
Step 3: Eliminate 50,000 Pa and 500,000 Pa
Pa would require m², and Pa would require m². Both are much larger than the given m², so both are incorrect.
Step 4: Select the correct answer
Only 5,000,000 Pa is consistent with Pa. This is the correct answer.
Question 2
Which of the following correctly explains why a drawing pin enters a noticeboard more easily than pressing with a flat coin, when the same force is applied to both?No clue? Show me the answer
Correct answer
Correct!
IncorrectStep-by-step walkthrough
Choose a solution method
Method #1Direct ApproachStep 1: Identify the key variable
The question states the same force is applied to both. So any difference in outcome must be due to the area of contact, not the force.
Step 2: Apply the pressure formula
From : if is constant and decreases, then increases. The drawing pin tip has a much smaller contact area than a flat coin.
Step 3: Select the correct answer
The drawing pin enters more easily because its smaller area concentrates the same force into a much higher pressure, which is enough to penetrate the board.
Method #2Process of EliminationStep 1: Identify what is being asked
The question asks why a drawing pin creates more penetration than a coin with the same applied force. We need to find the correct physics explanation.
Step 2: Eliminate the 'heavier' and 'harder material' options
The question specifies that the same force is applied to both objects. Weight and material hardness are irrelevant here because the force is deliberately kept equal in both cases.
Step 3: Eliminate 'larger area produces greater pressure'
This is the opposite of the correct relationship. From , a larger area with the same force gives lower pressure, not greater pressure.
Step 4: Select the correct answer
The only correct statement is that the drawing pin has a smaller area, which means the same force produces a greater pressure — enough to push into the board.
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