Answer:
The asteroid's acceleration at this point is
Step-by-step explanation:
The equation that governs the trajectory of asteroid is given by :

The velocity of asteroid is given by :

At some point during the trip across the screen, the asteroid is at rest. It means, v = 0
So,
Acceleration,
Put t = 0.971 s

So, the asteroid's acceleration at this point is
and it is decelerating.