Karsyn has a piece of wood that is 3 feet long. if she uses 2 and 13/16 feet to make a bookshelf, how many feet of wood does she have left?

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).