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Homework Statement
Two forces are acting on a mass. One of the forces is a 40.0 N force and the other force is 30.0 N at the angles shown below:
The magnitude of the force is:
a) 15.3 N
b) 15.6 N <-- correct answer
c) 46.6 N
d) 69.0 N
Homework Equations
Pythagorean Therom
Cosine, Sine
The Attempt at a Solution
Vector
X component
A ax = (30.0N) Cos 20.0 = 28.2 N
B bx = (40.0 N)Cos 40.0 N = 30.6 N
Y component
ay = (30.0N)Sin 20.0 = 10.3 N
by = (40.0 N) Sin 40.0N = 25.7 N
C = ax+bx = 58.8 N Cy = 36 N
C = cx^2 + cy^2
C = 58.8N^2 + 36 N^2
C = 69 N
I keep getting 69 N and its not the correct answer. The correct answer is 15.6. I'm following the directions from my notes, but it gives me 69 every time. Help! What am I doing wrong?