We know from Newtons law of force that
Work done = Force * Distance moved
We know from the question that
Force applied = 70 Newton
Distance moved = 9 meters.
Since the object is moving in the same direction as the force applied
So
Work done = Force * Distance moved
= 70 * 9 newton meters(Nm)
= 630 newton meters(Nm)
= 630 joules
"A" I think, not sure tho.
We actually cant, really. Black Holes are really very powerful and don't just happen in some random place in the cosmos. We have got shots of Black holes that you cannot even see, but all the other big black holes that look like something straight of a sci-fi movie that look real, are really just photo- shopped. good question. Hope This Helped.