Emily has a class assignment to study conservation of energy in collisions. She starts with two golf balls that hang from strings and hit each other when they swing. Emily finds she can also measure collisions between different masses, by placing small pieces of adhesive putty between the balls. She sticks four of the balls together and lets them collide with the fifth ball. Will the fifth ball rise higher than the height where the four balls started? Explain, in terms of Newton's third law of motion.

The large ground finch obtains food by cracking seeds. what is its short, strong beak an example? a) tendency toward perfection b) adaptation of a species over time c) selective use and disuse of an organ over time d) scarcity of recourses

What element does susan b. anthony include in this passage to strengthen her argument?

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?