Answer:
The distance of the first bright fringe is given as 
The distance of the second dark fringe from the central bright fringe is given as 
Explanation:
From the question we are told that
The slit separation distance is 
The distance of the slit from the screen is 
The wavelength is 
For constructive interference to occur the distance between the two slit is mathematically represented as

Where m is the order of the fringe which has a value of 1 for first bright fringe
Substituting values


For destructive interference to occur the distance between the two slit is mathematically represented as
![Y_D = [n + \frac{1}{2} ] \frac{\lambda D}{d}](https://tex.z-dn.net/?f=Y_D%20%20%3D%20%20%5Bn%20%2B%20%5Cfrac%7B1%7D%7B2%7D%20%5D%20%5Cfrac%7B%5Clambda%20D%7D%7Bd%7D)
m = 2
so the formula to get the dark fringe is 
Now substituting values
![Y_D = [ 1 + \frac{1}{2} ] * \frac{633 *10^{-9} * 3.23 }{0.00115}](https://tex.z-dn.net/?f=Y_D%20%3D%20%5B%201%20%2B%20%5Cfrac%7B1%7D%7B2%7D%20%5D%20%2A%20%5Cfrac%7B633%20%2A10%5E%7B-9%7D%20%2A%203.23%20%7D%7B0.00115%7D)


Answer:
This equation is based on twin paradox - a phenomena where one of the twin travels to space at a speed close to speed of light and the other remains on earth. the twin from the space on return discovers that the one on earth age faster.
Solution:
= 10 years
v = 0.8c
c = speed of light in vacuum
The problem can be solved by time dilation equation:
(1)
where,
t = time observed from a different inertial frame
Now, using eqn (1), we get:

t = 16.67 years
The age of the twin on spaceship according to the one on earth = 25+16.67 =41.66 years
I believe Isaac Newtons Law " Gravity ".
Answer:
d. 50 C
Explanation:
In this problem, we have to add 800 ml of water at 20 Celsius to 800 ml of water at 80 Celsius.
According to the 2nd law of thermodynamics, heat transfers from hot to cold temperature.
The quantity of both the different waters is equal so this makes it very easy. All we have to do is find the mean of both the temperatures:
Final temperature = (20 C + 80 C)/2
= 50 Celsius