What is the tension in the pulley's rope.

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

The plum pudding model of the atom state that ?

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.