The answer is c. 4 seconds
Answer:
6.5 × 10¹⁵/ cm³
Explanation:
Thinking process:
The relation 
With the expression Ef - Ei = 0.36 × 1.6 × 10⁻¹⁹
and ni = 1.5 × 10¹⁰
Temperature, T = 300 K
K = 1.38 × 10⁻²³
This generates N₀ = 1.654 × 10¹⁶ per cube
Now, there are 10¹⁶ per cubic centimeter
Hence, 
Moisture content is measured in terms of pounds of water per pound of air (lb water/lb air) or grains of water per pound of air (gr. of water/lb air).
Hope this helps❤
Answer:
The lowest point of the curve is at 239+42.5 ft where elevation is 124.16 ft.
Explanation:
Length of curve is given as

is given as

The K value is given from the table 3.3 for 55 mi/hr is 115. So the value of A is given as

A is given as

With initial grade, the elevation of PVC is

The station is given as

Low point is given as

The station of low point is given as

The elevation is given as

So the lowest point of the curve is at 239+42.5 ft where elevation is 124.16 ft.
Answer:
d. 90%
Explanation:
As we know that internal combustion engine produce lot's of toxic gases to reduce these toxic gases in the environment a device is used and this device is know as current modeling converter.
Generally the efficiency of current model catalytic converter is more than 90%.But the minimum efficiency this converter is 90%.
So option d is correct.
d. 90%