(a)[2]
Show that the SI base units for viscosity are $\text{kg m}^{-1}\text{s}^{-1}$.
(b)[2]
A sphere of radius $3.0\,\text{cm}$ is moving straight down at terminal velocity of $2.0\,\text{m s}^{-1}$ through the liquid. The drag force on the sphere is $0.096\,\text{N}$. Calculate the viscosity of the liquid.
(c)[2]
On Fig. 1.1, draw and label arrows that show the directions of the three forces acting on the sphere as it falls through the liquid at terminal velocity.
(d(i))[2]
The density of the liquid is $920\,\text{kg m}^{-3}$. Show that the upthrust on the sphere is $1.0\,\text{N}$.
(d(ii))[2]
Calculate the mass of the sphere.