By Newtons Third law this is an action reaction pair of force
So the momentum is the same
30*20=50*x where x is velocity
x= 12m/s
direction is towards left since they act in opposite directions
Three things that effect a life system would be
- sunlight
-water
-energy/food
Hope this helps
I haven't worked on Part-A, and I don't happen to know the magnitude of the gravitational force that the Sun exerts on the Earth.
But whatever it is, it's exactly, precisely, identical, the same, and equal to the magnitude of the gravitational force that the Earth exerts on the Sun.
I think that's the THIRD choice here, but I'm not sure of that either.