Calculate the center of mass of 4 objects having masses of 18 kg, 5 kg, 8 kg and 22 kg which are located along the x-axis at positions xi-0.6 m, x2--0.2 m, xy- 0.5 m and x41.2 m, respectively. a 0.17 kg cue ball strikes the rail of a pool table at a speed of 8 m/s, rebounding with a velocity of 6 m/s. a) calculate the impulse delivered to the ball by the pool table. b) what average force would produce this impulse, if the total time duration of the impact is 20 msec? (1 msec 1 millisecond- 0.001 sec) 10. 1. the equation of motion describing the angular position of a spinning wheel is given by the expression o(t)-12t-3t (rad]. what is the total angular displacement in degrees from t-4 sec to t-6 sec?

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

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.