Answer:

Explanation:
It is given that,
The number of lines per unit length, N = 900 slits per cm
Distance between the formed pattern and the grating, l = 2.3 m
n the first-order spectrum, maxima for two different wavelengths are separated on the screen by 2.98 mm, 
Let d is the slit width of the grating,



For the first wavelength, the position of maxima is given by :

For the other wavelength, the position of maxima is given by :

So,



or

So, the difference between these wavelengths is 14.3 nm. Hence, this is the required solution.
Answer:
Large above ground mausoleums were not common in the elite Shang burials.
Explanation:
Large, above the ground mausoleums were not common so the answer is option B.
We can solve for the acceleration by using a kinematic equation. First we should identify what we know so we can choose the correct equation.
We are given an original velocity of 24 m/s, a final velocity of 0 m/s, and a time of 6 s. We and looking for acceleration (a) in m/s^2.
The following equation has everything we need:

So plug in the known values and solve for a:
0 = 24 + 6a
-24 = 6a
a = -4 m/s^2
Answer: the correct option is D (17m).
Explanation: The farthest distance at which a typical "nearsighted" frog can see clearly in air is 17m.
Answer:
Graph for object that is not moving: B
Graph for object that is speeding up: D
Explanation:
A.) In order to represent that an object is not moving, you must either show that there is no velocity (0 m/s) or show a position over time graph that is a horizontal line.
Because the position is the same as time increases, the graph shows that there the object must be at rest, as there is no change in position due to velocity. (Velocity must be 0m/s)
B.) In order to represent an object is speeding up, the position time graph must either be a positive exponential function, the velocity time graph must be a positive, linear line, or the acceleration over time graph must be a positive, horizontal line.
Why is D the correct answer? Because if an object is speeding up, you know that the value of its speed (velocity) is increasing at some rate. And since speeding up refers to positive change, the function of velocity over time graph must be a positive function.