Cereals are usually fortified with three most common minerals and vitamins which are:
1- Iron
2- Vitamin D
3- Vitamin B-12
Comparing the above to the given choices, we will find that the best answer is:
b. iron
The speed at which sound travels through the gas in the tube is 719.94m/s
<u>Explanation:</u>
Given:
Frequency, f = 11999Hz
Wavelength, λ = 0.03m
Velocity, v = ?
Sound speed in the tube is calculated by multiplying the frequency v by the wavelength λ.
As the sound loudness changed from a maximum to a minimum, then we know the sound interference in the case changed from constructive interference (the two sound waves are in phase, i.e. peaks are in a line with peaks and so the troughs), to a destructive interference (peaks coinciding with troughs). The least distance change required to cause such a change is a half wavelength distance, so:
λ/2 = 0.03/2
λ = 0.06m
We know,
v = λf
v = 0.06 X 11999Hz
v = 719.94m/s
Therefore, the speed at which sound travels through the gas in the tube is 719.94m/s
Answer:
1) Option D is correct.
The electric field inside a conductor is always zero.
2) Option A is correct.
The charge density inside the conductor is 0.
3) Charge density on the surface of the conductor at that point = η = -E ε₀
Explanation:
1) The electric field is zero inside a conductor. Any excess charge resides entirely on the surface or surfaces of a conductor.
Assuming the net electric field wasn't zero, current would flow inside the conductor and this would build up charges on the exterior of the conductor. These charges would oppose the field, ultimately (in a few nanoseconds for a metal) canceling the field to zero.
2) Since there are no charges inside a conductor (they all reside on the surface), it is logical that the charge density inside the conductor is also 0.
3) Surface Charge density = η = (q/A)
But electric field is given as
E = (-q/2πε₀r²)
q = -E (2πε₀r²)
η = (q/A) = -E (2πε₀r²)/A
For an elemental point on the surface,
A = 2πrl = 2πr²
So,
η = -E ε₀
Hope this Helps!!!
If the wall doesn't move, its mean that <u>the work he did is 0 J</u>.
<h3>Introduction</h3>
Hello my friend ! Here, I will help you. Alright, before it, I will to introduce to you about work (physics). In the world of physics, <u>work is the amount of force exerted to cause an object to move a certain distance from its starting point</u>. The amount of work will be proportional to the increase in force and increase in displacement. Amount of work can be calculated by this equation :
With the following condition :
- W = work (J)
- F = force (N)
- s = shift or displacement (m)
<h3>Proof</h3>
How about a stationary object like a wall pushed by Mr. Avalos ? Yes it is 0 J. Let's prove it!
Give :
- F = force of Mr. Avalos = 150 N
- s = displacement of wall = 0 m
- t = interval of the time = 60 s
Asked : W = work = ... J
Proven :
(Q.E.D)
<h3>See More :</h3>