Answer: "To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells."
Answer:
31. Seatbelts lock in place to make sure you don't go flying into the windshield.
32. Friction causes the soccer ball to slow down. If we were to kick a soccer ball in space, where there is no friction, it would keep on rolling until it eventually hits something or goes out of sight.
33. Heavier loads will make the vehicle move off of the table. The heavier the weight, the quicker the vehicle will roll. Loads that are something very similar or lighter than the vehicle won't make the vehicle move by any means.
34. Gravity is the power pulling the piano toward the Earth.
Friction would happen with an unpleasant surface, making it a lot harder to push the piano up the ramp.
35. Wagon C
Wagon C has the least boxes and minimal measure of mass, making it simplest to move.
36. I would move the crates so every cart has a similar measure of boxes, making them equivalent in mass. This would make them all take a similar measure of power to move them.
Explanation: I have the answer key
An enormous cloud of gas and dust that contracts due to gravity and forms stars is called a nebula.
