3. a person of mass 3m is standing on the left edge of a long, uniform board of mass m and length l
that is floating in water, as shown in the figure below. the person walks slowly to the right edge of
the board. the water exerts no drag forces on the board. find the position of the center of mass of
the board when the person is at the right edge of the board,

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.