http://www.webassign.net/userimages/barrett.3@osu/prelab-131-07A.gif [Broken] If A = 34 cm and the pendulum bob diameter is 2.4 cm, what is the appropriate height difference magnitude to use for evaluating the change in potential energy of the pendulum bob-earth system? I got 29 cm by subtracting 5 cm from A. It was correct. Suppose B = 22 cm. The distance traveled by the box, modeled as a point particle, is: I got 80 cm, logical, it was correct. Suppose the friction force between the table and the box is 0.16 N and B = 22 cm. What is the work done by friction on the box? The last part I have no idea what to do. I thought I could just multiply the friction force by the distance and I would get the distance traveled but that didn't work. Mass isn't given in the problem so what do I do?