A box of negligible mass rests at the left end of a 2.00-m, 25.0-kg plank (Fig. 11.21). The width of the box is 75.0 cm, and sand is to be distributed uniformly throughout it. The center of gravity of the nonuniform plank is 50.0 cm from the right end. What mass of sand should be put into the box so that the plank balances horizontally on a fulcrum placed just below its midpoint? Figure 11.21 Exercise 11.3.
