An autonomous research probe descends into a liquid methane ocean on Saturn's moon Titan. The density of liquid methane is ρ=450 kg m−3\rho = 450\text{ kg m}^{-3}ρ=450 kg m−3 and the surface gravitational field strength of Titan is g=1.35 m s−2g = 1.35\text{ m s}^{-2}g=1.35 m s−2. The atmospheric pressure at the surface is p0=150 kPap_0 = 150\text{ kPa}p0=150 kPa.
The probe plots a graph of the total pressure PPP (measured in kPa\text{kPa}kPa) on the vertical axis against the depth ddd (measured in m\text{m}m) on the horizontal axis.
Which of the following equations represents this relationship?
P=0.61d+150P = 0.61 d + 150P=0.61d+150
P=610d+150P = 610 d + 150P=610d+150
P=0.61dP = 0.61 dP=0.61d
P=150d+0.61P = 150 d + 0.61P=150d+0.61
54 exam-style questions on Edexcel GCSE Physics 15.2 Pressure in fluids, covering 15.2.1 Atmospheric pressure and height, 15.2.2 Pressure in fluids, 15.2.3 Pressure, force and area, 15.2.4 Pressure and depth, 15.2.5 Pressure in liquids: depth and density, 15.2.6 Upthrust, and 15.2.7 Floating and sinking. Each one has a worked solution and a mark scheme showing where the marks go.