Cassie volunteers at an animal shelter. She needs a total of 40 hours of volunteer time for a class. So far, she has volunteered for 18.5 hours. How many more hours does she need to volunteer?​

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).