Use the parallelogram rule to find the magnitude of the resultant force for the two forces shown in the figure. Round to
one decimal place.
-Suppose you would like to cross a 212 -foot wide river in a boat. Assume that the boat can travel 39 $\mathrm { mph }$ relative to the water and that the current is flowing west at the rate of $6 \mathrm { mph }$. What bearing should be chosen so that the boat will land at a point exactly across from its starting point? Give your answer to the nearest tenth of a degree.
A) $8.8 ^ { \circ }$
B) $81.2 ^ { \circ }$
C) $7.1 ^ { \circ }$
D) $5.9 ^ { \circ }$

Question

Quizplus · Accepted Answer

The correct answer is A because the parallelogram rule states that the magnitude of the resultant force is equal to the square root of the sum of the squares of the two forces. In this case, the two forces are 39 mph and 6 mph, so the magnitude of the resultant force is sqrt(39^2 + 6^2) = 40.1 mph.

Use the Parallelogram Rule to Find the Magnitude of the Resultant