Bradley went on a bike ride to the store 6 miles away. If it took Bradley 3/8 of an hour to get there and 1/4 of an hour to get back, what was his average rate of speed (miles per hour) for the entire trip?

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).