[SOLVED] 2003 AP physics mechanics problem Can someone help me figure out the first mechanics problem on the 2003 AP Physics C exam? I'm doing this for review. See post #3 for what I have so far. "http://www.collegeboard.com/prod_downloads/ap/students/physics/physics_c_m_frq_03.pdf" [Broken] or http://www.collegeboard.com/prod_downloads/ap/students/physics/physics_c_m_frq_03.pdf Here it is if you don't like clicking links: The 100kg box shown above is being pulled along the x-axis by a student. The box slides across a rough surface, and its position x varies with time according to the equation x=.5t^3+2t, where x is in meters and t is in seconds. a. Determine the speed of the box at time t=0. b. Determine the following as a function of time t. i) The kinetic energy of the box ii) The net force acting on the box iii) The power being delivered to the box c. Calculate the net work done on the box in the interval t=0 to t=2s. d) Indicate below whether the work done on the box by the student in the interval t=0 to t=2s would be greater, less than, or equal to the answer in part c).