Explanation:
Formula for black body radiation is as follows.

where, P = power emitted
A = surface area of black body
= Stephen's constant = 
As area is given as 1.0
. Converting it into meters as follows.
(as 1 m = 100 cm)
= 
It is given that P = 201 watts. Hence,
= 
= 
T = 
= 8862.5 K
Thus, we can conclude that the temperature of the surface is 8862.5 K.
The balloon would be smaller and not float as well because of the low temperature. The particles in the balloon when in the car will slow down and get closer together because of the low temperature. That caused it to become more dense and smaller in size then before. When in the store, the particulars in the balloon we’re moving faster and more spread apart
I am not to sure because I have not studied this