find the resultant force magnitude and angle from adding f1f
find the resultant force magnitude and angle from adding f1+f2+f3
160 lbs at 45 degrees
90 lbs at 100 degrees
105 lbs at 290 degrees
Solution
f1 = 160 cos 45o i + 160 sin 45o j
= 160 (1/ square root of 2) i + 160 (1/ square root of 2) j
= 160(0.707) i + 160 (0.707) j = 113.13 i + 113.13 j
f2 = 90 cos 100o i + 90 sin 100o j
= 90 ( -0.173) i + 90 ( 0.984) j
= -15.628 i + 88.63 j
f3 = 105 cos 290o i + 105 sin 290o j
= 105(0.342) i + 105( -0.939)j
= 35.91 i - 98.66 j
resultant force is f =f1 + f2 + f3
= 113.13 i + 113.13 j + -15.628 i + 88.63 j + 35.91 i - 98.66 j
= i( 113.13 -15.628 +35.91 ) + j(113.13+88.63- 98.66)
resultant force, f = 133.412 i + 103.1 j
magnetude of f is square root of (133.4122 + 103.12)
= square root of ( 17798.76 + 10629.61) = 168.6
angle of f is tan-1( 103.1 / 133.412)
= 37.69o
therfore, the resultant force has a magnetude of 168.6, at an angle of 37.69 degrees.
