A student determines the density of an unknown liquid by measuring the hydrostatic pressure at the bottom of a vertical column of height 0.80 m.
The pressure sensor used has a systematic zero error: it reads +1.5 kPa when the pressure is zero. With the column filled, the sensor shows a reading of 9.5 kPa.
Using g=9.81 m s−2g = 9.81\text{ m s}^{-2}g=9.81 m s−2, what is the actual density of the liquid, and how does the student's calculated density (if they fail to correct for the zero error) compare to the actual density?
Actual density is 1020 kg m−31020\text{ kg m}^{-3}1020 kg m−3; the calculated density is too large.
Actual density is 1020 kg m−31020\text{ kg m}^{-3}1020 kg m−3; the calculated density is too small.
Actual density is 1210 kg m−31210\text{ kg m}^{-3}1210 kg m−3; the calculated density is too small.
Actual density is 1400 kg m−31400\text{ kg m}^{-3}1400 kg m−3; the calculated density is too large.
44 exam-style questions on Edexcel IGCSE Physics Density and pressure. Each one has a worked solution and a mark scheme showing where the marks go.