Pressure in liquids and gases
4 marks · NormalThe pressure due to the atmosphere is about 100,000 Pa. A rectangular hatch on a submarine has an area of 0.24 m².
Calculate the total force exerted by the atmosphere on the hatch.
The submarine dives so there is sea water on the other side. State one factor that will increase the force on the hatch.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) 24,000 N · must show Substitute into F = p × A, Correct answer
(b) Increasing the depth of water (or area of the hatch, or density of water) · must show Mentions increasing depth, area, or density
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Substitutes correctly into F = p × A
A1 (a) · 1 mark · Correct evaluation: 24,000 N (follow-through)
B1 (b) · 2 marks · States any valid factor that increases force (depth, area, density)
Worked solution
a) N
b) Increasing the depth of water will increase the pressure, and hence the force.