Jamey is taking a test that has 57 questions. So far, she has answered 48 questions correctly. How many more questions must she answer correctly, so that her total score of questions answered correctly will be 90%? Assume she can't get partial credit for any problem.

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).