Ben visits the park every 2 days and goes to the library every 5 days. if ben gets to do both of these today, how many days will pass before ben gets to do them both on the same day again?

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).