Two forces with magnitudes of 150 and 75 pounds act on an object at angles of 30° and 150° respectively. Find the direction and magnitude of the resultant force. Round to two decimal places in all intermediate steps and in your final answer.

Verified Answer :

F_x = 150cos 30 - 75cos 30 = 64.95
F_y = 150sin 30 + 75sin 30 = 112.5

R = sqrt(64.95^2 + 112.5^2) = sqrt(16874.75) = 129.90
Direction of R is arctan(112.5/64.95) = arctan(1.73) = 59.97°

Answer:

Magnitude= 129.55N

Direction= 60°

Step-by-step explanation:

In order to find the magnitude, we must find the magnitude in both vertical and horizontal direction.

In horizontal direction: \(f_{x}\)=150cos30°+ 75cos150°

=\(150\)×\(\frac{\sqrt{3} }{2}\) +\(75\)×\(-\frac{\sqrt{3} }{2}\)

=\(129.90-64.95\)

=\(64.95N\)

In vertical direction: \(f_{y}\)= 150sin30°+75sin150°

=\(150\)×\(\frac{1}{2}\)+\(75\)×\(\frac{1}{2}\)

=\(112.50N\)

Thus, magnitude is given by: \(\sqrt{f_{x} ^{2}+f_{y} ^{2} }\)

=\(\sqrt{64.25^{2}+112.50^{2}  }\)

=\(\sqrt{16784.31}\)

=\(129.55N\)

Direction of the force is calculated as: tanα=\(\frac{f_{y} }{f_{x} }\)

=\(\frac{112.50}{64.95}\)

=\(1.7321\)

α=60°