When the bones have atrophy remodeling, what happens to their strength?

A person yells across a canyon and hears an echo 2.5 seconds later. The air temperature is 21°C. How far away is the canyon wall

Alchen [17]

Answer: The canyon wall is 850 m away from the person

Explanation:

Well, the speed of sound $V$ in air at $21 \° C$ is defined as $343.60 m/s$ , this can be calculated by the following equation:

$V=\sqrt{\frac{\gamma R T}{M}}$ (1)

Where:

$\gamma=1.4$ is the Heat capacity ratio for air

$R=8.314 J/mol.K$ is the Universal Gas constant

$T=21 \° C+273.15=294.15 K$ is the temperature in Kelvin

$M=0.029 kg/mol$ is the air molar mass

$V=\sqrt{\frac{(1.4)(8.314 J/mol.K)(294.15 K)}{0.029 kg/mol}}$

$V=343.60 m/s$ (2)

Now that we know the speed of sound, we can use the following equation to find the distance between the person and the canyon wall:

$V=\frac{d}{t}$ (3)

Where:

$d$ is the distance between the person and the canyon wall

$t=2.5 s$ is the time it takes to the sound wave to travel from the person and then go back

Isolating $d$ :

$d=V.t$ (4)

$d=(343.60 m/s)(2.5 s)$ (5)

Finally:

$d=850 m$

7 0

3 years ago

Does lightning McQueen have car or life insurance?

shutvik [7]

I am taking an educated guess that he has life insurance

7 0

3 years ago

Which object has the least amount of kinetic energy? a car driving down a road a soccer ball rolling down a hill a bicycle locke

mars1129 [50]

<span> a bicycle locked to a bike rack im pretty sure</span>

7 0

3 years ago

Read 2 more answers

Suppose you push horizontally with precisely enough force to make the block start to move, and you continue to apply the same am

Tcecarenko [31]

Answer:

Incomplete question,

This is the complete question

Suppose you push horizontally with precisely enough force to make the block start to move, and you continue to apply the same amount of force even after it starts moving. Find the acceleration ~a of the block after it begins to move. Express your answer in terms of some or all of the variables µs, µk, and m, as well as the acceleration due to gravity g.

Explanation:

Let the force that make the object to start moving be F,

Frictional force is opposing the motion, the body has to overcome two frictional forces acting in the opposite direction of the motion.

Also, weight and normal reaction are acting in vertical direction, the weight is acting downward while the reaction is acting upward.

Weight of the object is given as

W=mg

Analyzing the vertical motion i.e y-axis.

ΣF = ma

since the body is not moving upward, the a=0

N-W=0

Then, N=W

So, N=mg

So, from friction law

Fr=µN

For static

Fs=µsN

For kinetic or dynamic

Fk= µkN

Using newton law

Along x-axis

Before the body start moving we can get the Force and since the force is the same use to start the block in motion.

Then,

ΣF = ma

Since at static the body is not moving then, a=0

F-Fs=0

F=Fs

Since, Fs=µsN

F=Fs=µsN

Then, the force to keep the body in motion too is F=µsN

Now analyses when the body is in motion

ΣF = ma

F-Fk=ma

ma=F - Fk

Substituting F=µsN and Fk=µkN

ma=µsN - µkN

ma=N(µs - µk)

Since N=mg

Then, ma=mg(µs - µk)

m cancels out, then

a=g(µs - µk)

Then the acceleration of the body is given as "a=g(µs - µk)"

5 0

3 years ago

Cathode ray tubes (CRTs) used in old-style televisions have been replaced by modern LCD and LED screens. Part of the CRT include

Ket [755]

Answer:

E = 1.64 x 10⁶ V/m

Explanation:

The electric field in the region between the plates can be given by the following formula:

$E = \frac{\Delta V}{d}$

where,

E = Electric Field = ?

ΔV = Poetential Difference across the plates = 23 KV = 23000 V

d = distance between plates = 1.4 cm = 0.014 m

Therefore, using these values in the equation, we get:

$E = \frac{23000\ V}{0.014\ m}$

5 0

3 years ago