Hi there!
Normal rain has a pH between 5.0 and 5.5, which is slightly acidic on the pH scale. Acid rain on the other hand has an average pH of 4.0, much more acidic than your average rain.
Therefore, the most likely pH of acid rain would be 4.0.
Let distance be x.
Time in going, t 1 = x/50
Time in coming, t 2 = x/40
Total time T = x/40 +x/50 = 9x/200
Average speed = total distance/ total time
=( x+x)/(9x/200)= 2x ×200/9x = 400/9 = 44.44 km/h
We can solve the problem by using the ideal gas equation:

where
p is the pressure of the gas
V is the volume of the gas
n is the number of moles of the gas
R is the gas constant
T is the absolute temperature of the gas
For the gas in our problem, we have:




If we rearrange the equation and we put these numbers into it, we find the volume of the gas:
Answer:
a) 20.54 J
b) 30.97 J
c) 10.43 J
d) -20.54 J
Explanation:
m = Mass
g = Acceleration due to gravity = 9.81 m/s²
h = Height

Work done by the ball's weight is 20.54 J

Gravitational potential energy of the basketball, relative to the ground, when it is released is 30.97 J

Gravitational potential energy of the basketball, relative to the ground, when it is released is 10.43 J
Change in gravitational potential energy

Change in gravitational potential energy is given by -20.54 J