<span>9.50x10^2 newtons
A pascal is defined as 1 newton per square meter. So let's multiply the pressure by the surface area of the box lid.
F = 1.00x10^-2 m^2 * 9.50x10^4 N/m^2 = 9.50x10^2 N
So it will take 9.50x10^2 newtons of force to remove the lid from the box.</span>
Answer:
r₂ = 0.2 m
Explanation:
given,
distance = 20 m
sound of average whisper = 30 dB
distance moved closer = ?
new frequency = 80 dB
using formula
![\beta = 10 log(\dfrac{I_1}{I_0})](https://tex.z-dn.net/?f=%5Cbeta%20%3D%2010%20log%28%5Cdfrac%7BI_1%7D%7BI_0%7D%29)
I₀ = 10⁻¹² W/m²
now,
![30 = 10 log(\dfrac{I_1}{10^{-12}})](https://tex.z-dn.net/?f=30%20%3D%2010%20log%28%5Cdfrac%7BI_1%7D%7B10%5E%7B-12%7D%7D%29)
![\dfrac{I_1}{10^{-12}}= 10^3](https://tex.z-dn.net/?f=%5Cdfrac%7BI_1%7D%7B10%5E%7B-12%7D%7D%3D%2010%5E3)
![I_1= 10^{-8}\ W/m^2](https://tex.z-dn.net/?f=I_1%3D%2010%5E%7B-8%7D%5C%20W%2Fm%5E2)
to hear the whisper sound = 80 dB
![80 = 10 log(\dfrac{I_2}{10^{-12}})](https://tex.z-dn.net/?f=80%20%3D%2010%20log%28%5Cdfrac%7BI_2%7D%7B10%5E%7B-12%7D%7D%29)
![\dfrac{I_2}{10^{-12}}= 10^8](https://tex.z-dn.net/?f=%5Cdfrac%7BI_2%7D%7B10%5E%7B-12%7D%7D%3D%2010%5E8)
![I_2= 10^{-4}\ W/m^2](https://tex.z-dn.net/?f=I_2%3D%2010%5E%7B-4%7D%5C%20W%2Fm%5E2)
we know intensity of sound is inversely proportional to square of distances
![\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}](https://tex.z-dn.net/?f=%5Cdfrac%7BI_1%7D%7BI_2%7D%3D%5Cdfrac%7Br_2%5E2%7D%7Br_1%5E2%7D)
![\dfrac{10^{-8}}{10^{-4}}=\dfrac{r_2^2}{20^2}](https://tex.z-dn.net/?f=%5Cdfrac%7B10%5E%7B-8%7D%7D%7B10%5E%7B-4%7D%7D%3D%5Cdfrac%7Br_2%5E2%7D%7B20%5E2%7D)
![10^{-4}=\dfrac{r_2^2}{20^2}](https://tex.z-dn.net/?f=10%5E%7B-4%7D%3D%5Cdfrac%7Br_2%5E2%7D%7B20%5E2%7D)
r₂ = 0.2 m
![V= \frac{S}{t}](https://tex.z-dn.net/?f=V%3D%20%5Cfrac%7BS%7D%7Bt%7D%20)
![t= \frac{S}{V}](https://tex.z-dn.net/?f=t%3D%20%5Cfrac%7BS%7D%7BV%7D%20)
<u />
![t= \frac{S}{c}](https://tex.z-dn.net/?f=t%3D%20%5Cfrac%7BS%7D%7Bc%7D%20)
![t= \frac{6.1*10^{12}}{299792458}](https://tex.z-dn.net/?f=t%3D%20%5Cfrac%7B6.1%2A10%5E%7B12%7D%7D%7B299792458%7D%20)
![t=20347.4098071s](https://tex.z-dn.net/?f=t%3D20347.4098071s)
It takes 20347.4098071s for light from the sun to reach Pluto.
The 6.1*10^9 is replaced by 6.1*10^12 on line 4 because we convert the distance from km to m.
c = speed of light. If a different value was given in the previous question then use that instead of the value I used to do the final calculation.
The electromagnetic spectrum includes a continuous spectrum of wavelengths that include:
Radio waves, microwaves, infrared light, visible, ultraviolet, X-rays, gamma rays
The wavelength decreases from radio waves to gamma rays, whereas the energy increases along the same direction.
In the given example, radio waves have a lower energy and higher wavelength than visible light. The latter can be perceived by the human eye, whereas radio waves are not visible to the human eye.
1) They have colors = visible light
2) They can travel in a vacuum = both
3) They have energy = both
4) They’re used to learn about dust and gas clouds = radio waves
5) They’re used to find the temperature of stars = visible light
6)They’re invisible = radio waves