Answer
See explanation.
Work Step by Step
a. $\lambda_2=h\sqrt{\frac{8L^2}{2(1^2)h^2}}$
$\lambda_1=6.0\times10^{-10}m$. The wavelength is twice that of the width of the box.
The momentum is $p_1=\frac{h}{\lambda_1}=1.1\times10^{-24}\;kg \cdot m/s$.
b. $\lambda_2=h\sqrt{\frac{8L^2}{2(2^2)h^2}}$
$\lambda_2=3.0\times10^{-10}m$. The wavelength is the same as the width of the box.
The momentum is $p_2=\frac{h}{\lambda_2}=2.2\times10^{-24}\;kg \cdot m/s$.
c. $\lambda_3=h\sqrt{\frac{8L^2}{2(3^2)h^2}}$
$\lambda_3=2.0\times10^{-10}m$. The wavelength is two-thirds the width of the box.
The momentum is $p_3=\frac{h}{\lambda_3}=3.3\times10^{-24}\;kg \cdot m/s$.