An ecosystem is all the populations of organisms that live together and
a. the microorganisms that depend on them.
b. the organisms that generate energy from sunlight.
c. the physical factors with which they interact.
d. the food that they take in as energy.

Acatapult is tested by roman legionnaires. they tabulate the results in a papyrus and 2000 years later the archaeological team reads (distances translated into modern units): range = 0.4 km; angle of launch = π/5 rad; landing height = launch height. what is the initial velocity of launch of the boulders if air resistance is negligible?

Look at the potential energy diagram for a chemical reaction. which statement correctly describes the energy changes that occur in the forward reaction?

Why should seat belts not be mandatory quick plz