Answer:
Decreases by 
times
Explanation:
The intensity of a sound is defined as the energy of the sound that is flowing in an unit time through the unit area which is in the direction that is perpendicular to the direction of the sound waves movement.
The intensity of energy is described by the inverse square law. It states that the intensity varies inversely with the distance square of the distance.
In other words, the sound intensity decreases as inversely proportional to the squared of the distance. i.e. 
In the context when the distance was 3 m, the intensity of the sound was = 
But when the distance became 6 cm or 0.06 m, the sound intensity decreases by = 
= times
The answer for the following problem is explained below.
Therefore the volume charge density of a substance (ρ) is 0.04 × 
C.
Explanation:
Given:
radius (r) =2.1 cm = 2.1 ×
m
height (h) =8.8 cm = 8.8 × m
total charge (q) =6.1×
C
To solve:
volume charge density (ρ)
We know;
<u> ρ =q ÷ v</u>
volume of cylinder = π ×r × r × h
volume of cylinder =3.14 × 2.1 × 2.1 ×
× 8.8 ×
volume of cylinder (v) = 122.23 ×
<u> ρ =q ÷ v</u>
ρ = 6.1× ÷ 122.23 ×
<u>ρ = 0.04 × </u><u> C</u>
Therefore the volume charge density of a substance (ρ) is 0.04 × C.
Answer:
Tycho Brahe
Explanation:
Tycho Brahe's accurate observations of planetary positions provided the data used by Johannes Kepler to derive his three fundamental laws of planetary motion.
Answer:
0.25miles/min
Explanation:
Instantaneous speed of a person or an object is its speed at a particular moment usually at a period of time.
The speedometer of a car reports the instantaneous speed.
It can be mathematically expressed as;
Instantaneous speed = 
At 20min the distance covered is 5miles;
Instantaneous speed = 
= 0.25miles/min
