Answer:
The equation which describes conservation of charge is 
Explanation:
The law of conservation charge states that for an isolated system that sum of initial charges is equal to sum of final charges, that is the total charge is conserved.
let the sum of initial charges = 
let the sum of the final charges = 

Therefore, the equation which describes conservation of charge is 
A set of two forces that are in opposite directions, have equal magnitudes and act on different objects
Answer:
The second ball lands 1.5 s after the first ball.
Explanation:
Given;
initial velocity of the ball, u = 12 m/s
height of fall, h = 35 m
initial velocity of the second, v = 12 m/s
Time taken for the first ball to land;

determine the maximum height reached by the second ball;
v² = u² -2gh
at maximum height, the final velocity, v = 0
0 = 12² - (2 x 9.8)h
19.6h = 144
h = 144 / 19.6
h = 7.35 m
time to reach this height;

Total height above the ground to be traveled by the second ball is given as;
= 7.35 m + 35m
= 42.35 m
Time taken for the second ball to fall from this height;

total time spent in air by the second ball;
T = t₁ + t₂
T = 1.23 s + 2.94 s
T = 4.17 s
Time taken for the second ball to land after the first ball is given by;
t = 4.17 s - 2.67 s
T = 1.5 s
Therefore, the second ball lands 1.5 s after the first ball.
To solve this problem, we know that:
1 psi = 6894.76 Pa
1 lb / ft^2 = 47.88 Pa
Therefore:
a. 1500 x 10^3 Pa * (1 lb / ft^2 / 47.88 Pa) = 31,328.32 lb
/ ft^2
b. 1500 x 10^3 Pa * (1 psi / 6894.76 Pa) = 217.56 psi