Answer:
c) 10.7m/s
Explanation:
From the exercise we know that at 5m the ball is traveling at 4m/s
To calculate its initial velocity we need to solve the following equation:

Since the initial height is 0
Solving for 

Velocity is height , speed is an object being propelled by force
The ratio of concentration of ionized acid to the initial concentration of acid multiplied by 100 will give the percent ionization of a weak acid in water increases as the concentration of acid decreases.
Explanation:
Percent ionization is used for quantifying the number of ions present in the weak acid when dissolved in a solution. So it is similar to the pKa value. The percent ionization value can be determined as negative log of dissociation constant. Also the as the number of ions increases in weak acid, the concentration of acid will be decreasing . It can be calculated using the formula for percent ionization as follows:

As the water volume or concentration increases, the acid will get diluted much more thus leading to decrease in the concentration of acid.
So the ratio of concentration of ionized acid to the initial concentration of acid multiplied by 100 will give the percent ionization of a weak acid in water increases as the concentration of acid decreases.
Answer:
D.
Explanation:
Specifically, Special Relativity showed us that space and time are not independent of one another but can be mixed into each other and therefore must be considered as the same object, which we shall denote as space-time. The consequences of space/time mixing are: time dilation. and length contraction.