The force of gravity between two objects is given by:

where
G is the gravitational constant
m1 and m2 are the masses of the two objects
r is their separation
In this problem, the mass of the object is

, while the Earth's mass is

. Their separation is

, therefore the gravitational force exerted on the object is
Answer:
Joel has the faster speed.
Explanation:
Joel has a steeper slope on the graph. The steeper a slope is, the faster speed will be. Therefore, Joel's slope is steeper which increases overall speed.
During either one, the sun, moon, and Earth are lined up in the same straight line. The difference is whether the moon or the Earth is the one in the "middle".
Answer: A. Object A will have a positive charge.
Explanation: If the number of protons and electrons are the same, their net charges cancel each other out, and you have a neutral charge. If electrons are transferred to another object, the amount of positive charge will outweigh the amount of negative charge. As a result, you are left with an overall positive charge in object A. Meanwhile, object B is now negative.