Question

A physical quantity Q depends upon three quantities x, y and z as $Q=\frac{x^2{y}^{1/2}}{z};$ In a particular set of measurements, x is measured with +50% error, y is measured with –36% error and z is measured with –20% error. The percentage error in the calculation of Q in this set of measurements is 25n%. Find the value of n.

Answer 1

$Q=\frac{x^2{y}^{1/2}}{z}$

$Q^{\prime }=\frac{2.25x^2{\left(0.64\right)}^{1/2}{y}^{1/2}}{0.8z}$

(\Rightarrow\) 125% error