State the law of conservation of energy

The desk has a weight of 75 lb and a center of gravity at g. determine the initial acceleration of a desk when the man applies enough force f to overcome the static friction at a and b. also, find the vertical reactions on each of the two legs at a and at b. the coefficients of static and kinetic friction at a and b are ms = 0.5 and mk = 0.2, respectively

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration

At what time will the interfering waves have an amplitudeof zero?