Question

5. a) Define viscosity.

b) A matter has a body-centered cubic unit cell with a length of 330 𝑝𝑚 along an edge

and a density of 8.57 𝑔 𝑐𝑚−3

. Calculate the atomic mass of the matter.

c) Find the total energy of a moving object of mass 6.3 𝑘𝑔 and momentum

11.5 × 106 𝑘𝑔𝑚𝑠

−1

Answer 1

a) The viscosity of a fluid is a measure of its resistance to deformation at a given rate.

b)

$$(3.3\cdot10^{-10})^2=\frac{2M}{8.57\cdot6.023\cdot10^{23}}\\M=93$$

c)

$$E=\frac{p^2}{2m}\\E=\frac{(11.5\cdot10^6)^2}{2(6.3)}=1.05\cdot10^{13}\ J$$