The formula for potential energy is
E(p) = mgh
(Mass x gravity x height)
Therefore energy = (5.3)(9.8)(6.6)
= 342.8 J
How did I get 9.8?
9.8 is the constant for gravity
Mirrors reflect light waves.
As it is given that the air bag deploy in time

total distance moved by the front face of the bag

Now we will use kinematics to find the acceleration




now as we know that

so we have

so the acceleration is 400g for the front surface of balloon