The head of a thumbtack has an area of 500 mm² - Leaving Cert Physics - Question b - 2008
Question b
The head of a thumbtack has an area of 500 mm².
Its point has an area of 0.3 mm².
The pressure exerted at the head of the thumbtack is 12 Pa.
What is the pressure ex... show full transcript
Worked Solution & Example Answer:The head of a thumbtack has an area of 500 mm² - Leaving Cert Physics - Question b - 2008
Step 1
At head:
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Answer
To find the force exerted at the head of the thumbtack, we can use the formula for pressure:
F=P×A
Here, the pressure (P) at the head is 12 Pa, and the area (A) of the head is 500 mm²:
F=12 Pa×(500×10−6m2)
Calculating this gives:
F=12×500×10−6=6.0×10−3 N
Step 2
At point:
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Answer
Now, we need to calculate the pressure exerted at the point of the thumbtack using the same force we calculated before. The area of the point is 0.3 mm²:
Using the pressure formula again:
P=AF
Substituting the values gives:
P=(0.3×10−6m2)6.0×10−3 N
Calculating the pressure:
P=0.3×10−66.0×10−3=2.0×104 Pa
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