The first question's answer is :
If, F=ma
Then, 15N= 2.1kg (a)
15/2.1=a
7.14=a
Therefore, acceleration = 7.14m/s^2
sorry I am not sure about the second question :-(
When the moon faces earth a solar eclipse happens :-)
The answer is A. Commensalism. <span>Commensalism, in ecology, is a class of relationships between two organisms where one organism benefits from the other without affecting it. This was the briefest answer from Wiki. Hope it helps, and sorry I'm late.</span>
