Beth made the chart shown.

a 2-column table with 1 row. the first column labeled x has entries wall clock, t v remote control, portable music player. the second column labeled y has entries refrigerator, table lamp, hair dryer.
which headings best complete the chart?

x: use dc
y: use ac

x: use ac
y: use dc

x: powered by current
y: powered by magnetism

x: powered by magnetism
y: powered by current

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.)