How do you find the volume of a cardboard box this is 12 cm long, 2cm wide and 3 cm high?

Need solving this 2nd limit problem.

Solve the equation for b: a= (1/2)(b)(h)

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).