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.

Respuesta :

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: [tex]f_{x}[/tex]=150cos30°+ 75cos150°

=[tex]150[/tex]×[tex]\frac{\sqrt{3} }{2}[/tex] +[tex]75[/tex]×[tex]-\frac{\sqrt{3} }{2}[/tex]

=[tex]129.90-64.95[/tex]

=[tex]64.95N[/tex]

In vertical direction: [tex]f_{y}[/tex]= 150sin30°+75sin150°

=[tex]150[/tex]×[tex]\frac{1}{2}[/tex]+[tex]75[/tex]×[tex]\frac{1}{2}[/tex]

=[tex]112.50N[/tex]

Thus, magnitude is given by: [tex]\sqrt{f_{x} ^{2}+f_{y} ^{2} }[/tex]

=[tex]\sqrt{64.25^{2}+112.50^{2}  }[/tex]

=[tex]\sqrt{16784.31}[/tex]

=[tex]129.55N[/tex]

Direction of the force is calculated as: tanα=[tex]\frac{f_{y} }{f_{x} }[/tex]

=[tex]\frac{112.50}{64.95}[/tex]

=[tex]1.7321[/tex]

α=60°