Ask question

Ask question

All categories

3 years ago

10

Relativistic kinetic energy is conserved in all reference frames. True O False

1 answer:

Free_Kalibri [48]3 years ago

7 0

Answer:

i think it is true

Explanation:

You might be interested in

A fan at a rock concert is 50.0 m from the stage, and at this point the sound intensity level is 114 dB. Sound is detected when

Marianna [84]

Answer:

A) $P=13.92\ J.s^{-1}$

B) $v=3730.9912\ m.s^{-1}$

C) $v=74.44\ mm.s^{-1}$

D) mosquitoes speed in part B is very much larger than that of part C.

Explanation:

Given:

Distance form the sound source, $s=50\ m$

sound intensity level at the given location, $\beta=114\ dB$

diameter of the eardrum membrane in humans, $d=8.4 \times 10^{-3}\ m$

We have the minimum detectable intensity to the human ears, $I_0=10^{-12}\ W.m^{-2}$

(A)

<u>Now the intensity of the sound at the given location is related mathematically as:</u>

$\beta=10\ log(\frac{I}{I_0} )$ ..........................................(1)

$114=10\ log\ (\frac{I}{10^{-12}} )$

$11.4=log\ I+12\ log\ 10$

$I=0.2512\ W.m^{-2}$

<em>As we know :</em>

$I=\frac{P}{A}$

$0.2512=\frac{P}{\pi\times \frac{8.4^2}{4} }$

$P=13.92\ J.s^{-1}$ is the energy transferred to the eardrums per second.

(B)

mass of mosquito, $m=2\times 10^{-6}\ kg$

<u>Now the velocity of mosquito for the same kinetic energy:</u>

$KE=\frac{1}{2} m.v^2$

$13.92=\frac{1}{2}\times 2\times 10^{-6}\times v^2$

$v=3730.9912\ m.s^{-1}$

(C)

Given:

Sound intensity, $\beta = 20\ dB$

<u>Using eq. (1)</u>

$20=10\ log\ (\frac{I}{10^{-12}} )$

$2=log\ I+12\ log\ 10$

$I=10^{-10}\ W.m^{-2}$

Now, power:

$P=I.A$

$P=10^{-10}\times \pi\times \frac{8.4^2}{4}$

$P=5.54\times 10^{-9}\ J.s^{-1}$

Hence:

$KE=\frac{1}{2} m.v^2$

$5.54\times 10^{-9}=0.5\times 2\times 10^{-6}\times v^2$

$v=0.07444\ m.s^{-1}$

$v=74.44\ mm.s^{-1}$

(D)

mosquitoes speed in part B is very much larger than that of part C.

7 0

3 years ago

Use Newton’s first law to explain why a book on a desk does not move

rewona [7]

Answer:

nothing moves if anything other doesn't move it.

natural position of things is the resting

Explanation:

yeah that's it

5 0

3 years ago

Read 2 more answers

Using the same cost and time estimates, consider the time-effectiveness of each engineer.

sammy [17]

Answer:

Camilla

Explanation:

I got it right on edge. :)

4 0

3 years ago

Why is a microscope or magnifying glass used to view objects close up instead of moving the object closer to your

Shalnov [3]

Answer:

D; The microscope and magnifying glass block out the light, which allows the naked eye to focus on the object.

Explanation:

This is to prevent chromatic abberation

8 0

3 years ago

A 35.0 g bullet strikes a 5.3 kg stationary wooden block and embeds itself in the block. The block and bullet fly off together a

Alisiya [41]

Answer:

= 1200m/s or 1.2 x $10^{3}$ m/s

Explanation:

3 0

3 years ago