Answer : The speed in miles per hour is 22 mile/hr.
The speed in yard per min is 26617.8 yard/min
Explanation :
The conversion used for meters to miles is:

The conversion used for second to hour is:

The conversion used for meter per second to mile per hour is:

As we are given the speed of 407.0 meter per second. Now we have to determine the speed in miles per hour.

So, 
Therefore, the speed in miles per hour is 22 mile/hr.
The conversion used for meter to yard
1m = 1.09 yard
The conversion used for second to hour is:

The conversion used for meter per second to mile per hour is:


As we are given the speed of 407.0 meter per second. Now we have to determine the speed in yards per min

So, 
Therefore, the speed in yard per min is 26617.8 yard/min
The answer is B. Decreasing the cylinder volume decreases the amount of space the gas has to occupy there for increasing pressure
Answer is: the hydronium ion concentratio is 1.71×10⁻⁷ mol/dm³ and pH<6.76.
The Kw (the ionization constant of water) at 40°C is 2.94×10⁻¹⁴ mol²/dm⁶ or 2.94×10⁻¹⁴ M².
Kw = [H₃O⁺] · [OH⁻].
[H₃O⁺] = [OH⁻] = x.
Kw = x².
x = √Kw.
x = √2.94×10⁻¹⁴ M².
x = [H₃O⁺] = 1.71×10⁻⁷ M; concentration of hydronium ion.
pH = -log[H₃O⁺].
pH = -log(1.71×10⁻⁷ M).
pH = 6.76.
pH (potential of hydrogen) is a numeric scale used to specify the acidity or basicity an aqueous solution.
B. Because there are 3 molecules in right and 2 molecules in the left, so entropy rises.