Pressure under a solid
2 marks · EasyA student places a brick weighing 60 N flat on the ground.
The area of contact is 0.15 m². Calculate the pressure exerted by the brick on the ground.
If the student stands the brick on its end, the area of contact becomes 0.05 m², but the weight is unchanged. Explain what happens to the pressure and why.
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(a) 400 Pa
(b) Pressure increases because the area decreases while force stays the same.
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Correct calculation: 60 / 0.15 = 400 Pa (accept units).
B1 (b) · 1 mark · Explanation: pressure increases as area decreases for the same force.
Worked solution
(a) Pressure = Force / Area = 60 N / 0.15 m² = 400 Pa
(b) When area decreases and force is the same, pressure increases.