Answer:

Explanation:
From the question we are told that:
Height of window 
Height of window off the ground 
Time to fall and drop
Generally the Newton's equation motion is mathematically given by

Where



Generally the Newton's equation motion is mathematically given by

Where





Therefore the ball’s initial speed

Answer:
The wavelength of the light is 562.5 nm
Solution:
As per the question:
Order, n = 1
Slit separation, d = 
Distance from the bright fringe, y = 0.18 m
Distance between the screen and the grating, D = 0.8 m
Now,
We know from the eqn for diffraction:

n = 1
(1)
Also,
For very small angle,
:
≈ 
Using the above value in eqn (1):

The water was heavier since it was more concentrated