Which statement is correct for the reaction below?

4x+z yields 2r+2s
a: the rate of formation of r is one-half the rate of the disappearance of z.
b: the rate of disappearance of z is one-fourth of the rate of disappearance of x.
c: the rate of formation of r is double the rate of formation of s.
d: the rate of formation of s is double the rate of disappearance of x.

Imagine that a new planet is discovered with two moons of equal mass: moon a and moon b. the mass of the new planet is greater than the combined mass of its moons. moon a is farther away from the new planet than moon b. what is the planet's gravitational pull on moon a compared to the planet's gravitational pull on moon b? the planet's gravity repels moon a with a greater force than it repels moon b, which is why moon a is farther away. the gravitational pull on moon b is greater than on moon a because moon b is closer to the new planet than moon a. the gravitational pull on moon b is greater than on moon a because moon b is farther away from the new planet than moon a. the gravitational pull on moon a is the same as the gravitational pull on moon b because distance does not affect the planet's gravity.