1 point

A horse was grazing at the top of a small hill. The horse got thirsty and ran toward a

Phoenix [80]

Answer:

I think it may be decreased, but i'm in 6th grade so-

Explanation:

7 0

3 years ago

In general, if a sound has intensity of β dB at 1 m from the source, at what distance from the source would the decibel level de

Tpy6a [65]

Answer: The required distance is given by

$r_2=1\text{ m}\cdot 10^\frac{\beta}{20}.$

Explanation: The sound intensity in dB is given by the formula

$\beta \text{ dB}=10\log\frac{I}{I_0}$

where $I_0$ is the hearing threshold in absolute units and $I$ is the absolute intensity of the sound which depends on the distance. In general, for two distances $r_1$ and $r_2$ we have that

$\frac{I(r_1)}{I(r_2)}=\frac{r_2^2}{r_1^2}=\left(\frac{r_2}{r_1}\right)^2.$

Now let us take $r_1=1\text{ m}$ and let $r_2$ be the required distance. We have

$\beta \text{ dB}=10\log\frac{I(r_1)}{I_0},\quad 0\text{ db}=10\log\frac{I(r_2)}{I_0}.$

Exponentiating these equations we obtain

$10^{\frac{\beta}{10}}=\frac{I(r_1)}{I_0},\quad 10^0=1=\frac{I(r_2)}{I_0}.$

Dividing them

$\frac{I(r_1)}{I(r_2)}=10^\frac{\beta}{10}.$

Using the previously stated identity

$\frac{r_2^2}{r_1^2}=10^\frac{\beta}{10}\Rightarrow r_2=r_110^\frac{\beta}{20}=1\text{ m}\cdot 10^\frac{\beta}{10}$

Now if we use the given example where $\beta=11$ we have

$r_2=1\text{ m}\cdot 10^{\frac{11}{20}}=3.55\text{ m}.$

7 0

3 years ago

Why are we able to use nuclear energy for practical purposes? The reactions are controlled to regulate energy output. The reacti

musickatia [10]

Answer: The reactions are controlled to regulate energy output

Explanation:

Nuclear energy is produced when either two nuclei fuse to produce larger nucleus or a bigger nuclei splits into two smaller nucleus.

Uranium easily splits to produce nuclear energy. The reactions are controlled and energy output can be regulated. Nuclear energy in abundant yet controlled amount is available. Nuclear energy is mostly used in steam turbines to produce electricity.

5 0

4 years ago

Read 2 more answers

A girl exerts a horizontal force of 109 N on a crate with a mass of 31.2 kg. HINT (a) If the crate doesn't move, what's the magn

vesna_86 [32]

Answer:

(a) Magnitude of static friction force is 109 N

(b) Minimum possible value of static friction is 0.356

Solution:

As per the question;

Horizontal force exerted by the girl, F = 109 N

Mass of the crate, m = 31.2 kg