314 Higher Engineering Mathematics
- The pressurepand volumevof a mass of gas
are related by the equationpv=50. If the pres-
sure increases from 25.0 to 25.4, determine the
approximate change in the volume of the gas.
Find also the percentage change in the volume
of the gas. [−0.032,−1.6%] - Determine the approximate increase in (a) the
volume, and (b) the surface area of a cube
of sidexcm ifxincreases from 20.0cm to
20.05cm. [(a) 60cm^3 (b) 12cm^2 ] - The radius of a sphere decreases from 6.0cm
to 5.96cm. Determine the approximate change
in (a) the surface area, and (b) the volume.
[(a)−6.03cm^2 (b)−18.10cm^3 ]
5. The rate of flow of a liquid through a
tube is given by Poiseuilles’s equation as:
Q=
pπr^4
8 ηL
where Qis the rate of flow, p
is the pressure difference between the ends
of the tube,ris the radius of the tube,L
is the length of the tube andηis the coeffi-
cient of viscosity of the liquid.ηis obtained
by measuring Q,p,r andL.IfQ can be
measured accurate to±0.5%,paccurate to
±3%,raccurate to±2% andLaccurate to
±1%, calculate the maximum possible per-
centage error in the value ofη.
[12.5%]