Outage Notification

In the Question 7, part b solution, the value for work W = 1.01 x 10^6 J is used as the value for force when calculating power.

Katherine, you're exactly correct, thank you for catching our error. All fixed.  John

Question 5 should state the block-incline-earth system if we are using AP conventions. If earth is not included in the system, the block incline system would have zero initial energy. I suggest editing the original question so you do not have to change the solution.

Michael, thanks very much - we are using AP conventions - and they've emphasized this point over the past few years. Corrected and posted.  John