The figure below shows the anatomical structures in the lower leg and foot that are involved in standing on tiptoe, with the heel raised slightly off the floor so that the foot effectively contacts the floor only at point P. Assume distance a = 6.5 cm, distance b = 19.5 cm, and the person's weight W = 636 N. Calf muscle Lower leg bones "B (a) Of the forces acting on the foot, what is the magnitude of the force point A from the calf muscle? (b) Of the forces acting on the foot, what is the direction of the force at point A from the calf muscle? O up O down (c) Of the forces acting on the foot, what is the magnitude of the force at point B from the lower leg bones?

1) A toy mobile is built like the one shown below. Object A has a 0.5-kg mass. What should be the mass of object B? The numbers indicate the relative lengths of the rods on each side of their supporting cords.

1) A toy mobile is built like the one shown below. B 2 3 1 2 1 1 Object A has a 1.0-kg mass. What should be the mass of object B? The numbers indicate the relative lengths of the rods on each side of their supporting cords.

1. ch A uniform 40.0-kg scaffold of length 6 m is supported by two light cables, as shown below. An 80 kg painter stands 1 m from the left end of the scaffold, and his painting equipment is 1.5 m from the right end. The tension in the left cable is twice that in the right cable. Find 1. The tension in the left cable = 2. The tension in the right cable = 3. The mass of the equipment = N 99+ N kg Think & Prepare 1. If the plank is in equilbrium, torque about any point will be zero. Pick a point about which to calculate torques. 2. Draw all forces and torques. 3. Write down the First Condition for Equilibrium symbolically. 4. Write down the Second Condition for Equilibrium symbolically. 5. How many unknowns are there? How many equations are there? 6. How can you solve the equations find the unkowns?