friction 1. i am hauling 230㎏ of firewood on a sled, puig with 710n of force on a rope over my shoulder at a 72 degree angle from the sled. the sled starts to accelerate at 0.12mis. what is the coefficient of friction between the ground and the sled? 2. there is a 4kg book sitting on a table. igive the book a push·ltstarts off sling at 25msec then slides to a stop in 1.7m. what is the coefficient of friction between the book and the table? 3. the 1992 1500kg mazda rx-7 could go from 60mph-0 in 119ft. what is the coefficient of friction between the tires and the tarmac? 4. i am walking down a 20 degree slope and i step on a banana peel with a kinetic coefficient of friction of 0.013. assuming i have a mass of 120kg, how fast do i start sliding down that hil?

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

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.