Pressure in Fluids: p = F/A, p = hρg and Upthrust Worked Examples | GCSE Physics

Pressure in fluids for GCSE Physics, animated: why a drawing pin goes in point first, and how a steel ship floats. Pressure = force ÷ area in pascals, with an original worked example (a 600 N person on two feet, then on one 1 cm² stiletto heel: 15 000 Pa vs 6 000 000 Pa) and the cm² to m² conversion that trips people up. OCR's hydraulics: 50 N on a small piston lifting 2500 N. Why pressure in a liquid grows with depth and density and pushes at right angles to every surface (a can with water jets), and why atmospheric pressure falls as you go higher. Then Higher tier: p = hρg, worked line by line (3.0 m down in a pool; a diver going from 2.0 m to 5.0 m in seawater), where upthrust comes from (the pressure difference between the top and bottom of an object), a 10 cm cube worked through to 9.8 N, and floating and sinking: why a block of density 600 kg/m³ floats 60% under. Four mistakes that cost marks. Covers: AQA 4.5.5 · Edexcel Topic 15 (15.7P–15.17P) · OCR Gateway P1.3f–j, P2.3n–o (separate Physics only on every board; p = hρg and upthrust are Higher tier; hydraulics is OCR only). 0:00 Intro 0:08 Hook 0:38 Pressure equals force over area 1:10 Worked example: feet and a heel 2:04 Hydraulics 2:50 Pressure in a liquid 3:20 Atmospheric pressure 3:47 p = hρg 4:38 Worked example: a pressure difference 5:17 Upthrust 5:47 Worked example: upthrust on a cube 6:37 Floating and sinking 7:13 Common mistakes 7:45 Summary Narrated with an AI voice. Worked Example is not affiliated with or endorsed by AQA, OCR or Pearson Edexcel. Exam board names are used only to show which specifications a video covers.