Answer:
X: Always attractive
Y: Infinite range
Z: Attractive or repulsive
ANSWER IS C
The average speed would be 33.29m/s.The average speed equation is:

First you will need to solve for the distance you traveled in each scenario. So we can solve this by getting the product of speed and the time traveled.
Scenario 1:
Speed = 29m/s
Time = 120s
Distance = ?
Distance = (29m/s)(120s)
= 3,480m
Scenario 2
Speed = 35m/s
Time = 300s
Distance = ?
Distance = (35m/s)(300s)
= 10,500m
Now that you have the distance of both, you can solve for your average speed.
Oil, grease and dry lubricants
An element refers to a collection of atoms having the same number of protons and electrons (an atomic number). In each element there is a different atomic number due to a different amount of protons in the nucleus.
An isotope is a variation of an element that contains a different number of neutrons, therefore adding weight to the atom.
An ion is a charged atom, and its charge shows how many electrons it needs to gain or lose in order to become stable.