When you add up (20N down) and (10N up),
you get a sum of (10N down).
The mass of the object has no effect on the forces.
Now ... I see 5 points for the answer.
Where are the other 25 coming from ?
The impulse (the variation of momentum of the ball) is related to the force applied by

where

is the variation of momentum, F is the intensity of the force and

is the time of application of the force.
Using F=1000 N and

, we can find the variation of momentum:

This

can be rewritten as

where

and

are the final and initial momentum. But the ball is initially at rest, so the initial momentum is zero, and

from which we find the final velocity of the ball:
Answer:
that is my question
Explanation:
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<h2>HOW OLD ARE YOU</h2>