Q. A door of width 1.01 and height 2.03 weighs 279 and is supported by two hinges, one a distance 0.500 from the top and the other a distance 0.500 from the bottom. Each hinge supports half the total weight of the door.

Q. Two strings, one having linear density and length L1, the other having linear density 3 and length L2, are tied at a knot shown by the "X", and the ends are attached to walls as shown. The strings are held under the same tension. The total length of the strings is 4 m. A physics student plucks the knot, sending waves traveling towards the walls. What must lengths L1 and L2 be if the waves reach the walls at the same time.