A Trough Has Vertical Ends That Are Equilateral Triangles with Sides

Multiple Choice

A trough has vertical ends that are equilateral triangles with sides of length $7 \mathrm { ft }$ . If the trough is filled with water to a depth of $4 \mathrm { ft }$ , find the force exerted by the water on one end of the trough. Round to one decimal place. (The weight density of water is $62.4 \mathrm { lb } / \mathrm { ft } ^ { 3 }$ .) Select the correct answer.

A) $\quad 384.3 \mathrm { lb }$
B) $1,337.7 \mathrm { lb }$
C) $768.6 \mathrm { lb }$
D) $2,675.4 \mathrm { lb }$