I need help with these problems. Thank you!

1. A gym-goer is holding a dumbbell statically while he snaps a quick selfie in the mirror. Here is what you know: o Elbow flexion angle = 90 o Distance from the elbow joint center to the external resistance = 40cm o Moment arm of the biceps = 2cm . External resistance = 20kg . The torque generated at the elbow due to the force of the biceps = 78.48Nm How much force must the biceps produce to hold this position? Use the following information to answer questions 2-4. An individual is performing a hamstring curl exercise and is positioned prone on a bench. Here is what you know: . Femur is horizontal o Knee flexed 25 above horizontal. o Mass of 15kg attached to the leg o The length of the tibia is 0.6m 2. What is the length of the moment arm of the ankle weight relative to the knee joint center? 3. How much torque is created at the knee by the ankle weight? 4. If the moment arm of the hamstring muscle is 0.05m, how much force must the hamstring muscles generate to keep the leg in a condition of static equilibrium