the diagram is being used to illustrate the second law of thermodynamics, where qh  represents a hot object and qcrepresents a cold object. which will  best  complete the diagram to illustrate the law? adding in the boxes an arrow that points from qh  to qcadding in the boxes an arrow that points from  qc  to  qhadding in the boxes an arrow that points in both directions between  qh  and  qcadding in each box an arrow that points upward fromqh  and from  qc

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)