Answer:
To solve this problem, we need to use vector addition. We can start by breaking down each force into its x and y components.
For muscle A:
Force = 100 lbs
Angle = 15 degrees
X-component = 100 * cos(15) = 96.93 lbs
Y-component = 100 * sin(15) = 25.04 lbs
For muscle B:
Force = 150 lbs
Angle = 30 degrees
X-component = 150 * cos(30) = 129.90 lbs
Y-component = 150 * sin(30) = 75.00 lbs
For muscle C:
Force = 75 lbs
Angle = 10 degrees
X-component = 75 * cos(10) = 73.83 lbs
Y-component = 75 * sin(10) = 13.03 lbs
Next, we can add up the x and y components separately:
X-component = 96.93 + 129.90 + 73.83 = 300.66 lbs
Y-component = 25.04 + 75.00 + 13.03 = 113.07 lbs
We can use these components to find the magnitude and direction of the resultant force:
Magnitude = sqrt(X^2 + Y^2) = sqrt((300.66)^2 + (113.07)^2) = 321.23 lbs
Direction = tan^-1(Y/X) = tan^-1(113.07/300.66) = 21.65 degrees (measured counterclockwise from the positive x-axis)
Therefore, the resultant force of the muscles is 321.23 lbs at an angle of 21.65 degrees. Here is a diagram to illustrate the vectors:
Explanation:
25.04 lbs 73.83 lbs 129.90 lbs
/\ /\ /\
/ \ / \ / \
/ \ / \ / \
100 lbs 15° 75 lbs 10° 150 lbs 30°
\ / \ / \ /
\ / \ / \ /
\ / \ / \ /
96.93 lbs 13.03 lbs 75.00 lbs