Answer:
The intensity of sound (I) = 3.16 x 10⁻⁶ W/m²
Explanation:
We have expression for sound intensity level (SIL),

Here we need to find the intensity of sound (I).

Substituting
L = 67 dB and I₀ = 10⁻¹² W/m² in the equation

The intensity of sound (I) = 3.16 x 10⁻⁶ W/m²
See the attached picture for answers
Explanation:
First we will convert the given mass from lb to kg as follows.
157 lb = 
= 71.215 kg
Now, mass of caffeine required for a person of that mass at the LD50 is as follows.

= 12818.7 mg
Convert the % of (w/w) into % (w/v) as follows.
0.65% (w/w) = 
= 
= 
Therefore, calculate the volume which contains the amount of caffeine as follows.
12818.7 mg = 12.8187 g = 
= 1972 ml
Thus, we can conclude that 1972 ml of the drink would be required to reach an LD50 of 180 mg/kg body mass if the person weighed 157 lb.
Answer: #4
Sally is faster.
Explanation:
If you multiply Sallies it is going to be less than Jessica's.