You and your classmates are experimenting with the pull of gravity on falling objects. You know from science class that if no air resistance is present, the rate of descent depends only on how far the object has fallen, no matter how heavy the object is. This means that two objects (a bowling ball and a pen) will reach the ground at the same time if they are dropped simultaneously from the same height. After multiple trials, objects continued to hit the ground at the same time when dropped from equal height, until the last trial. In the last trial, Hannah and Annie dropped an expo marker, a paperclip, and a notecard. The paperclip and the marker reached the ground at the same time, but the notecard was slower. What statement best explains their findings? A) The downward force of gravity is less on the notecard because it has less mass. B) The upward force of friction is greater on the notecard than the other objects. C) The upward force of air resistance is greater with the notecard causing it to reach the ground slower. D) There was an error in the experiment. All of the objects will reach the ground at the same time due to equal gravitational pull.

the answer is neither ball has a charge.

because if they were both positively charged, they will repel each other.

if they were positively and negatively charged, they will seek.

so here is the information for current research:

-nrel's geothermal analysts, scientists, and engineers perform a full range of research from developing advanced methods of locating and accessing geothermal resources to exploring innovative technologies to extract and produce clean energy from the heat of the earth

and here is the information for the technology of geothermal energy:

-it's clean and sustainable

-resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma

-almost everywhere, the shallow ground or upper 10 feet of the earth's surface maintains a nearly constant temperature between 50° and 60°f (10° and 16°c)

-geothermal heat pumps can tap into this resource to heat and cool buildings

-a geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger-a system of pipes buried in the shallow ground near the building

-in the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system

-in the summer, the process is reversed, and the heat pump moves heat from the indoor air into the heat exchanger

-the heat removed from the indoor air during the summer can also be used to provide a free source of hot water

moisture is lackin, and organic acids are scarce.