Which of the follow statements best describes the relationship between carrying capacity and population size?

A 60 year old person has a threshold of hearing of 95.0 dB for a sound with frequency f=10,000 Hz. By what factor must the inten

Nadusha1986 [10]

Answer:

The intensity increased by a factor of 158489

Explanation:

Given that,

Sound level = 95.0 dB

Sound level = 43.0 dB

Frequency = 10000 Hz

We need to calculate the ratio of sound intensity

Using formula of sound level

$sound\ level =10 log\dfrac{I}{I_{0}}$

Put the value into the formula

$95.0=10\ log\dfrac{I_{1}}{I_{0}}$ ...(I)

$43.0=10\ log\dfrac{I_{2}}{I_{0}}$ .....(II)

Subtracting these equations

$52.0=10\ log\dfrac{I_{1}}{I_{2}}$

$\log\dfrac{I_{1}}{I_{2}}=5.2$

Taking inverse log

$\dfrac{I_{1}}{I_{2}}=10^{5.2}$

$\dfrac{I_{1}}{I_{2}}=158489$

Hence, The intensity increased by a factor of 158489

4 0

2 years ago

If a child starts from rest at point A and lands in the water at point B, a horizontal distance L = 2.52 m from the base of the

tamaranim1 [39]

Answer:

The height of the water slide is 0.878 m

Explanation:

Given that,

Distance = 2.52 m

Suppose Children slide down a friction less water slide that ends at a height of 1.80 m above the pool.

We need to calculate the time

Using equation of motion

$s=ut+\dfrac{1}{2}gt^2$

Put the value in the equation

$1.80=0+\dfrac{1}{2}\times9.8\times t^2$

$t^2=\dfrac{1.80\times2}{9.8}$

$t=\sqrt{\dfrac{1.80\times2}{9.8}}$

$t=0.606\ sec$

We need to calculate the velocity

Using formula of velocity

$v = \dfrac{d}{t}$

Put the value into the formula

$v=\dfrac{2.52}{0.606}$

$v=4.15\ m/s$

We need to calculate height

Using conservation of energy

$\dfrac{1}{2}mv^2=mgh$

$h=\dfrac{v^2}{2g}$

Put the value into the formula

$h=\dfrac{4.15^2}{2\times9.8}$

$h=0.878\ m$

Hence, The height of the water slide is 0.878 m.

4 0

2 years ago

On a straight road (taken to be in the x direction) you drive for an hour at 60 km per hour, then quickly speed up to 120 km per

Luda [366]

Answer:

The average velocity is 180 km/hr

Explanation:

Given;

initial velocity, u = 60 km per hour

final velocity, v = 120 km per hour

initial time = 1 hour

final time = 2 hour

Initial position = 60 km/h x 1 hour = 60 km

final position = 120 km/h x 2 hour = 240 km

The average velocity is given by;

$V_{avg} = \frac{Final \ position\ - \ Initial \ position}{final \ time\ - \ initial \ time}\\\\V_{avg} = \frac{240km \ - \ 60km}{2hr\ - \ 1hr} \\\\V_{avg} = \frac{180 \ km}{1hr} \\\\V_{avg}= 180 \ km/hr$

Therefore, the average velocity is 180 km/hr

3 0

2 years ago

Why are some animals and plants can become pests when introduced into Australia

Yanka [14]

<span>Plants there are a lot. Australian plants are extremely hardy an have adapted to grow in conditions others have not. So when taken outside of Australia they do very, very well. Animals, less so. But there are a few very interesting cases.

</span>

8 0

3 years ago

If a marathon runner averages 9.51 mi/hr, how long does it take him to run a 26.220-mile marathon. Express your answers in hours

ASHA 777 [7]

Explanation:

Speed of the marathon runner, v = 9.51 mi/hr

Distance covered by the runner, d = 26.220 mile

Let t is the time taken by the marathon runner. We know that the speed of the runner is given by total distance divided by total time taken. Mathematically, it is given by :

$v=\dfrac{d}{t}$

$t=\dfrac{d}{v}$

$t=\dfrac{26.220\ mi}{9.51\ mi/hr}$

t = 2.75 hours

Since, 1 hour = 60 minutes

t = 165 minutes

Since, 1 minute = 60 seconds

t = 9900 seconds

Hence, this is the required solution.

7 0

2 years ago