The answer is D. Isotopes.
Hope that helped.
Answer:Force is to the right
Explanation: because the right side has 75N compared to the 25N on the left.
500 N is the answer, you just tell that the moon is attracted towards the person because of the Earth's huge mass.
Answer:

Explanation:
Given that
x= 150 ft

y= 14 ft
From the diagram

When ,x= 150 ft and y= 14 ft


z=150.74 ft

By differentiating with respect to time t


Here x is constant that is why


Now by putting the values in the above equation we get



Therefore the distance between balloon and observer increasing with 0.65 ft/s.