Answer:
d = 1.55 * 10⁻⁶ m
Explanation:
To calculate the distance between the adjacent grooves of the CD, use the formula, 
..........(1)
The fringe number, m = 1 since it is a first order maximum
The wavelength of the green laser pointer, 
= 532 nm = 532 * 10⁻⁹ m
Distance between the central maximum and the first order maximum = 1.1 m
Distance between the screen and the CD = 3 m
= Angle between the incident light and the diffracted light
From the setup shown in the attachment, it is a right angled triangle in which
Putting all appropriate values into equation (1)
1) First of all, we need to find the distance between the two charges. Their distance on the xy plane is
substituting the coordinates of the two charges, we get
2) Then, we can calculate the electrostatic force between the two charges
and
, which is given by
where
is the Coulomb's constant.
Substituting numbers, we get
and the negative sign means the force between the two charges is attractive, because the two charges have opposite sign.
Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as “upwelling.”
Upwelling occurs in the open ocean and along coastlines. The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom.
Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients “fertilize” surface waters, meaning that these surface waters often have high biological productivity. Therefore, good fishing grounds typically are found where upwelling is common.
Another (slightly more technical) name for kidney stones is "renal calculus".
I know this because we have met many times, and we are old friends.
