Answer:
the current is 0.5 amperes.
the resistance is 40 ohms
Explanation:
in series, the resistances add up. thus
total resistance = 5 + 15 +20
= 40 ohms
and since all are connected in series the current is given by
current = voltage/ total resistance
= 20/40
=0.5 ampere
Answer:
0.027 N
Explanation:
From the question,
According to Archimedes principle,
The buoyancy force on the material = weight of oil displaced by the solid cube = Upthrust on the solid cube.
Applying,
U =ρ×V×g................ Equation 1
Where U = Upthrust on the solid cube, ρ = density of oil, V = Volume of the solid cube, g = acceleration due to gravity
But,
V = l³................ Equation 2
Substitute equation 2 into equation 1
U = gρl³.............. Equation 3
Given: ρ = 820 kg/m³, l = 1.50 cm = 0.015 m
Constant: g = 9.8 m/s²
Substitute these values into equation 3
U = 820×0.015³×9.8
U = 0.027 N
<span>The question is asking to complete the sentence: index fossils are the remains of species that were once abundant and (...). Index fossils are used to be able to see that a certain layer of soil was from a particular period of time. This means that they could not have lived long - just for a short period in the geological history. Typically, index fossils were also geographically widespread, but it's not always the case</span>
Answer:
3.6 x 10^8 V
Explanation:
Q = 4 m C = 4 x 10^-3 C
r = 5 cm = 0.05 m
The formula for the potential at the surface is
Vs = K Q / r = (9 x 10^9 x 4 x 10^-3) / 0.05 = 7.2 x 10^8 V
The formula for the potential at the centre is
Vc = 3/2 Vs
Vc = 1.5 x 7.2 x 10^8 V = 10.8 x 10^8 V
The difference in potential is
V = Vc - Vs = 10.8 x 10^8 - 7.2 x 10^8 = 3.6 x 10^8 V
Since the Units presented are not in the International System we will proceed to convert them. We know that,
![1 mi/h = 0.447 m/s](https://tex.z-dn.net/?f=1%20mi%2Fh%20%3D%200.447%20m%2Fs)
So the speed in SI would be
![V=95mi/h(\frac{0.447m/s}{1mi/h})](https://tex.z-dn.net/?f=V%3D95mi%2Fh%28%5Cfrac%7B0.447m%2Fs%7D%7B1mi%2Fh%7D%29)
![V=42.465 m/s](https://tex.z-dn.net/?f=V%3D42.465%20m%2Fs)
The change in frequency when the wave is reflected is
![f'=f(1+\frac{V}{c})](https://tex.z-dn.net/?f=f%27%3Df%281%2B%5Cfrac%7BV%7D%7Bc%7D%29)
Or we can rearrange the equation as
![f' = f + f\frac{V}{c}](https://tex.z-dn.net/?f=f%27%20%3D%20f%20%2B%20f%5Cfrac%7BV%7D%7Bc%7D)
f' = Apparent frequency
f = Original Frequency
c = Speed of light
![f'-f = f\frac{V}{c}](https://tex.z-dn.net/?f=f%27-f%20%3D%20f%5Cfrac%7BV%7D%7Bc%7D)
![\Delta f = f\frac{V}{c}](https://tex.z-dn.net/?f=%5CDelta%20f%20%3D%20f%5Cfrac%7BV%7D%7Bc%7D)
Replacing,
![\Delta f = (10.525*10^9)(\frac{42.465}{3*10^8})](https://tex.z-dn.net/?f=%5CDelta%20f%20%3D%20%2810.525%2A10%5E9%29%28%5Cfrac%7B42.465%7D%7B3%2A10%5E8%7D%29)
![\Delta f =1489.8 Hz](https://tex.z-dn.net/?f=%5CDelta%20f%20%3D1489.8%20Hz)
Since the waves are reflected, hence the change in frequency at the gun is equal to twice the change in frequency
![\Delta f_T = 2 \Delta f](https://tex.z-dn.net/?f=%5CDelta%20f_T%20%3D%202%20%5CDelta%20f)
![\Delta f_T = 2(1489.8Hz)](https://tex.z-dn.net/?f=%5CDelta%20f_T%20%3D%202%281489.8Hz%29)
![\Delta f_T = 2979.63Hz](https://tex.z-dn.net/?f=%5CDelta%20f_T%20%3D%202979.63Hz)
Therefore the increase in frequency is 2979.63Hz