1. Two muscles in the back of the leg pull upward on the Achilles tendon, as shown in Figure. These muscles are called the medial and lateral heads of the gastrocnemius muscle. Find the magnitude and direction of the total force on the Achilles tendon. What type of movement could be caused by this force?
2. The upper leg muscle (quadriceps) exerts a force of 1200 N, which is carried by a tendon over the kneecap (the patella) at the angles shown in Figure. What is the direction and magnitude of the force exerted by the kneecap on the upper leg bone (the femur)?
