A crate is placed on a massless plank of 3 m in length and transported by two workers. One worker applies a 300 N vertical force at the left-hand end of the plank and the other one applies a 500 N vertical force at the right-hand end of the plank. Find i) the weight of the crate and ii) the position of the center of gravity.

A student glues a 45 g mass at the left extremity of a 1 m bar and a 15 g mass 10 cm from the right extremity. The small masses are considered point masses. The bar mass is 500 g, uniformly distributed along its length. The student is asked to balance the mass-bar combination horizontally on a pivot situated precisely below the combination center of gravity. At what distance from the right extremity must the pivot be placed?