3) A 100m track is marked off in meters. When a sprinter leaves the starting line, timers are started. The sprinter passes the 12m [E] mark at 1.8s and passes the 56m [E] mark at 6.7s. What was the sprinter’s velocity between those two positions?

Explanation:

A track 100m

The sprinter passes 12m mark in 1.8seconds

Let this be the initial point

d1 = 12m

t1 = 1.8seconds

And Passes the 56m mark in 6.7 seconds

Then, the second point is

d2 = 56m

t2 = 6.7 seconds

The sprinter velocity between this two position

Velocity is the rate of change of displacement

V = displacement / time taken

V = ∆x / ∆t

V = (x2 - x1) / (t2 - t1)

V = (56 - 12) / (6.7 - 1.8)

V = 44 / 4.9

V = 8.98 m/s

Then, the sprinter velocity between this two position is 8.98 m/s

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​

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