Acylinder contains oxygen at a pressure of 2.00 atm. the volume is 4.00 l, and the temperature is 300 k. assume that the oxygen may be treated as an ideal gas. the oxygen is carried through the following processes: (i) heated at constant pressure from the initial state (state 1) to state 2, which has t=450k. (ii) cooled at constant volume to 250 k (state 3). (iii) compressed at constant temperature to a volume of 4.00 l (state 4). (iv) heated at constant volume to 300 k, which takes the system back to state 1.

Aperson gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. the cart travels forward along the floor, gradually slowing as it moves. consider the horizontal force(s) on the cart while it is moving forward and slowing. which of the following statements is correct? (a) both a forward and a backward force are acting on the cart, but the forward force is larger. (b) only a forward force is acting which diminishes with time. (c) both a forward and a backward force are acting on the cart, but the backward force is larger. (d) only a backward force is acting, no forward force.