What forces are acting on a dropped book that falls to the ground? A Gravity Only

B Gravity and Air Resistance

C Air Resistance only

D Friction only

HURRY PLS

Where does all the water go? according to the environmental protection agency (epa), in a typical wetland environment, 39% of the water is outflow; 46% is seepage; 7% evaporates; and 8% remains as water volume in the ecosystem (reference: united states environmental protection agency case studies report 832-r-93-005). chloride compounds as residuals from residential areas are a problem for wetlands. suppose that in a particular wetland environment the following concentrations (mg/l) of chloride compounds were found: outflow, 60.4; seepage, 73.7; remaining due to evaporation, 26.4; in the water volume, 46.8. (a) compute the weighted average of chlorine compound concentration (mg/l) for this ecological system. (round your answer to one decimal place.) mg/l (b) suppose the epa has established an average chlorine compound concentration target of no more than 58 mg/l. does this wetlands system meet the target standard for chlorine compound concentration? yes. the average chlorine compound concentration (mg/l) is too high. yes. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is too high.

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation