What approximations or simplifying assumptions must you make in these calculations? (note: some of these choices are false because they are wrong physics! ) entry field with incorrect answer treat mars as though it were spherically symmetric. ignore the effects of the sun, which alters the gravitational force that one object exerts on another. treat the humans as though they were points or uniform-density spheres. use the same gravitational constant in (a) and (b) despite its dependence on the size of the masses.

Natural forces that can alter ecosystems include seasons and climate changes. t or f

While studying chemical reactions and conservation of matter, sarah's class conducted a variety of experiments. sarah and her lab partner found the mass of a wax candle and placed the candle in a flask. the students lit the candle and let it burn to completion. all that was left was wax and charred candle wick. per their teacher's instructions, the students found the mass of the products. their data can be seen in the data table. formulate a hypothesis the students could test to explain why the experiment did not support the law of conservation of matter. a) the students could repeat the experiment using different candles; there might have been a flaw in the candle. b) the experiment should be repeatable. the students should run several trials and then take an average of the after mass in each trial. c) the students should have someone in the class check their measurement skills as they repeat the experiment. they may have made an error using the balance. d) the students should burn the candle in a container that has some type of lid so that any gas that is a product of the reaction can be contained and massed. submit

Which is not an example of how an object gains elastic potential energy by stretching? a. jumping on a pogo stick b. pulling on a rubber band c. jumping on a trampoline