Answer:
this is just a guess bc i only looked at it for 5 seconds but i think 150 m/s
Displacement = 0, assuming that he runs back to original position
Average velocity is displacement/ time, since displacement =0, velocity is also 0
Answer:
the force will increase by a factor 2.25
Explanation:
The gravitational force between the two stars is given by:

where
G is the gravitational constant
m1, m2 are the masses of the two stars
r is the distance between the stars
If the distance is decreased by one-third, it means that the new distance is 2/3 of the previous distance

So the new force will be

So, the force will be 2.25 times the previous value.