If a student was spinning a key on a string around her head, the key would fly off in a straight line in one direction if she released the string. What Law does this is example demonstrate?
A Newton's fourth law of motion
B. Newton's first law of motion
C. Newton's third law of motion
D. Newton's second law of motion

when the velocity of a mass on a spring is zero, the acceleration is at a maximum .

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

the answer is c. the lower legs are levers, and the knees are fulcrums. the ankles hold the loads.