Question

Two muscles in the back of the leg pull upward on the Achilles tendon, as shown in the figure below. (These muscles are called the medial and lateral heads of the gastrocnemius muscle.)F2 = 210 N18°F1 = 210 N 18°Find the magnitude (in N) and direction (in degrees counterclockwise from the dotted line) of the total force on the Achilles tendon.-magnitude -directionWhat type of movement could be caused by this force?

Answer 1

The magnitude of the resultant force is 399.44 N and the direction of the forces is along y - axis.

The movement caused by the force will be up and down movement.

How to calculate the magnitude and direction of resultant force?

The sum of the forces acting in the x - direction is calculated as follows;

Fx = F₁x - F₂x

Fx = 210 x cos(72) - 210 x cos(72)

Fx = 0 N

The sum of the forces acting in the y - direction is calculated as follows;

Fy = F₁y + F₂y

Fy = 210 x sin(72) + 210 x sin(72)

Fy = 399.44 N

The magnitude of the resultant force is calculated as;

F = √ (399.44² + 0²)

F = 399.44 N

The direction of the forces is along y - axis which is vertical, and the movement caused by the force will be up and down movement.