Lesson: The Negative Mass Method

A uniform wire of length 135 cm was bent around five sides of a regular hexagon . Determine the distance between the center of gravity of the wire and the center of the hexagon.

A square of side length . Three masses of 610 g are placed at , , and . Find the coordinates of the centre of mass of the system.

A uniform lamina is in the form of a rectangle in which and . The corner , where is the midpoint of , was cut off. The resulting lamina was freely suspended from the vertex . Determine the size of the angle the side makes to the vertical when the lamina is hanging in its equilibrium position stating your answer to the nearest minute.

A uniform lamina was in the form of a rectangle such that and . The point was on such that the distance . The point was on . The triangle was cut out. The remaining lamina was stood vertically on the edge . Given that it was on the point of tipping over about , find the distance .

A uniform square-shaped board has a side length of 363 cm. Its diagonals meet at . The triangle was cut out of the board and the remaining part was suspended from a point, , on . Given that, when the body is hanging in its equilibrium position, is horizontal, calculate the length .