Answer:
you have probably missed some details in the question.
Answer:0.25 kg-m/s
Explanation:
Given
mass of blob 
initial velocity 
time of collision 
we know Impulse is equal to change in momentum
initial momentum 

Final momentum 
as final velocity is zero
Impulse 


Answer:
d. equal to one-fourth the acceleration at the surface of the asteroid.
Explanation:
The explanation is attached as a picture with this answer
Newton's law of universal gravitation is being used to compare the accelerations at the surface and at the top of the ball's path.
as it can be seen in the explanation that the proportional form of the equation is used because we do not need to necessarily use to final form with "G" for comparison calculations.
As per the given scenario only difference between the two points in the gravitational field is the distance from center of the spherical asteroid, i.e. r.
It is taken 2r for the top is the path. hence we obtain (1/4)g as our answer.