1. A person standing on the floor is leaning against a wall. The wall exerts on the person a force of 100 N in the horizontal direction. What other horizontal force keeps the person in equilibrium?
2. Torque is measured in Newton meters. Work can also be measured in Newton meters. What are the quantities measured in meters in the two cases?
3. What is the advantage of having gears in a bicycle?
4. A person is doing strength training of knee extensor muscles. He sits on a bench, with a weight attached to his ankle. In what position of the leg will the gravitational torque about the knee joint be maximum?