Pressure under a Solid
2 marks · NormalExplain, using the pressure equation, why a sharp knife is easier to use for cutting than a blunt knife.
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Must show: smaller area gives greater pressure, greater pressure makes cutting easier
Common mistakes: confusing force with area
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Marking points
B1 · 1 mark · States that sharp knife has smaller area (of edge in contact).
B2 · 1 mark · Relates smaller area to greater pressure for same force, making cutting easier.
Worked solution
A sharp knife has a smaller contact area than a blunt one, so for the same force, the pressure is greater (p = F/A). Greater pressure makes it easier to cut.