A 10N metre stick rest on pivot of 25 cm, and a boy hold the other end, exerting an upward force. the stick is loaded with 75N at 5cm, 27.5N at 5cm and 12.5N at 90 cm. calculate how much force the boy exert on sticks

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?