For a certain sample

PHYSICS · Multi-part · A Level · Physics · Measurements and their errors · Measurements and their errors

Problem

For a certain sample, the measured values are: mass

m = 50.0\,\text{g}\,\pm\,0.4\,\text{g}

and length

l = 20.0\,\text{cm}\,\pm\,0.2\,\text{cm}

. The quantity

Q

is defined as

Q = \dfrac{m^{2}}{l^{3/2}}

. (i) Calculate the fractional uncertainty in

Q

. (ii) Hence determine the absolute uncertainty in

Q

. Give your answers to two significant figures.