Option B is the correct answer.
MKS system gives the following units:
Distance ----- meters
Mass ----- Kilograms
Time ----- seconds
meter is basic unit for length measurement. smaller units are centimeter, millimeter, micrometer, bigger units are kilometer and so on.
kilogram is the basic unit for mass. smaller unit is gram.
second is the basic unit for time. Greater units are minutes, hours, smallest unit are micro second and so on.
This is a list of well known characteristics of acids:
1) acids increase the concentration of hydronum ions ([H3O+]) when dissolved in water
2) acids taste sour
3) many are corrosive (the higher the acidity the higher the corrosive property)
4) when acids react with some metals produce hydrogen gas
5) acids conduct electricity (due to the presence of hydronium ions)
6) acids neutralize bases
7) acids combine with bases to produce water and salt
8) acids lower the pH of solutions.
They do not feel sticky to the touch. Bases fell slippery but there is not that property of sticky sensation about acids, although some highly concentrated strong acids have high viscosity. You cannot touch highly concentrated strong acids.
Given: Mass m = 0.50 Kg; Force = Weight = mg F = (0.50 Kg)(9.8 m/s²)
F = 4.9 N
Displacement x = 3.0 cm convert to meter x = 0.03 m
Required: Spring constant k = "
Formula: F = kx
k = F/x
k = 4.9 N/0.03 m
k = 163.33 N/m
Remember that sound intensity decreases in inverse proportion to the distance squared. So, to solve this we are going to use the inverse square formula:

where

is the intensity at distance 2

is the intensity at distance 1

is distance 2

is distance 1
We can infer for our problem that

,

, and

. Lets replace those values in our formula to find

:





dB
We can conclude that the intensity of the sound when is <span>3 m from the source is
30 dB.</span>