Force, work, and energy problems!! k im kind of pissed off because i just started getting the hang of this physics stuff and understanding everything going on with momentum, acceleration and velocity changes, etc... but now that we moved on to forces, energy, and work, its been nothing but headaches for me . for example, 1 question asks me.... A force acts on a 2.0 kg cart while the cart moves 1.2 m. the work done by the force during the motion is 3.0 J. When the force begins to act on the cart, the cart is already moving with a speed of 1.0 m/s. (a) What is the kinetic energy of the cart at the end of the 1.2 m motion? show calculations, etc... what i did for this was say E<i> was KE<i> and E<f> was KE<f> so i said KE<i> = KE<f> which makes no sense because if there is an extra force they cant be equal... can anyone help?! (b) What is the speed of the cart at the end of the motion? Show calculations, etc... (I could not answer this question because i dont know how to do part A) SOMEONE HELP ME!!!! THANKS!