Answer:
The range of angles is from 17.50° to 31.76°
Explanation:
The diffraction grid equation is as follows:

Clearing for 


where
is the angle,
is the order, in this case
,
is the wavelength, and
is defined as follows:

and since the resolution is 750 lines/mm wich is the same as 
will be:

wich is the distance between each line of the diffraction grating.
substituting the values for
and
:

And we need to find two angle values: one for when the wavelength is 400nm and one for when it is 700 nm. So we will get the angle range

and

The range of angles is from 17.50° to 31.76°
Because there is no record of all things. As we have partially unknow information, it can never be held as a fact.
Answer:
The concave mirror is a converging mirror so that it is used for many purposes, It is used as a torch to reflect the light, It is used in the aircraft landing at the airports to guide the aeroplanes, It is used in shaving to get an enlarged and erect image of the face.
Explanation:
Answer:
20.96 m/s^2 (or 21)
Explanation:
Using the formula (final velocity - initial velocity)/time = acceleration, we can plug in values and manipulate the problem to give us the answer.
At first, we know a car is going 8 m/s, that is its initial velocity.
Then, we know the acceleration, which is 1.8 m/s/s
We also know the time, 7.2 second.
Plugging all of these values in shows us that we need to solve for final velocity. We can do so by manipulating the formula.
(final velocity - initial velocity) = time * acceleration
final velocity = time*acceleration + initial velocity
After plugging the found values in, we get 20.96 m/s/s, or 21 m/s