Chapter 1.7, Problem 19P

A)

Interpretation Introduction

Interpretation:

The pressure exerted by the solar panel array on the roof.

Concept Introduction:

The force $\left(F\right)$ exerted on the solar panels.

$F=Mg$

Here, mass of the panels is $M$, and acceleration due to gravity is $g$.

The area $\left(A\right)$ of the roof.

$A=lw$

Here, length of the roof is $l$, and the width is $w$.

The pressure $\left(P\right)$ exerted by the solar panel array on the roof.

$P=\frac{F}{A}$

B)

Interpretation Introduction

Interpretation:

Estimate the total pressure on the roof if 4 inches snow fall on top of the solar panel

Concept Introduction:

Density of snow:

${\rho }_{\text{snow}}=30\%{\rho }_{\text{water}}$

Here, density of water is ${\rho }_{\text{water}}$.

The volume of snow $\left(V_{\text{snow}}\right)$:

$V_{\text{snow}}=lwh$

Here, height is $h$.

The force $\left(F\right)$ exerted by snow on the roof.

$F_{\text{snow}}=V_{\text{snow}}{\rho }_{\text{snow}}g$

the total pressure $\left(P_{\text{total}}\right)$ on the roof.

$P_{\text{total}}=\frac{F_{\text{snow}}+F}{A}$