Answer: 2.83 minutes
Explanation:
It is understood that trains are approaching. That is, they have speeds of equal magnitude but opposite. When train A travels x meters northbound, then train B travels the same distance southbound.
Therefore trains approach at a speed of:

Then:

Where x is the distance between the trains

So the time in which both trains meet is:

This is:

<em />
<em>How long will it be before they reach one another ?</em>
<h3>2.83 minutes</h3>
Answer:
8.40 m/s
Explanation:
Slope of the plot is 0.119
Slope of a plot is given by the change in y direction divided by the change in x direction
Here, the y axis represents inverse wavelength and the x axis represents frequency.
f = Frequency (Hz, assumed)
v = Phase velocity (m/s, assumed)
λ = Wavelength (m, assumed)
So, slope

Now,


The speed of sound travelling in the tube is 8.40 m/s
Answer:

The Magnitude of electric field is in the upward direction as shown directly towards the charge
.
Explanation:
Given:
- side of a square,

- charge on one corner of the square,

- charge on the remaining 3 corners of the square,

<u>Distance of the center from each corners</u>


∴Distance of center from corners, 
Now, electric field due to charges is given as:

<u>For charge
we have the field lines emerging out of the charge since it is positively charged:</u>

<u>Force by each of the charges at the remaining corners:</u>

<u> Now, net electric field in the vertical direction:</u>


<u>Now, net electric field in the horizontal direction:</u>


So the Magnitude of electric field is in the upward direction as shown directly towards the charge
.
Answer:
Option A
Explanation:
Ernest Rutherford concluded that the atom has a small, dense center which constitutes the mass of the whole atom. He called it a "Nucleus". He also said that most of the space in the atom is empty.