Question

$KE$ per unit volume is $E$ . The pressure exerted by the gas is given by

• A. $\frac{E}{3}$
• B. $\frac{2E}{3}$
• C. $\frac{3E}{2}$
• D. $\frac{E}{2}$

Answer 1

Answer: (B)

$\frac{2E}{3}$

Answer 2

The pressure exerted by the gas,
$p = \frac{1}{3} \, p \overline{c^2}$
$= \frac{ 1 m}{ 3 \, V} \overline{c^2}$
$= \frac{2}{3} \bigg( \frac{1}{2} m \overline{c^2} \bigg)$
$( \therefore \frac{1}{2} m \overline{c^2} = \frac{E}{V} =$ energy per unit volume, V = 1)
p= $\frac{2}{3}$ E