Answer:

Explanation:
y = Distance from the center point
d = Separation between slits = 0.3 mm
D = Distance between slit and screen = 1.5 m
= Wavelength = 700 nm
m = Order = 1
We have the relation

The distance from the screen at which the first bright fringe beyond the center fringe appear is
.
Answer:
t=2s
Explanation:
The definition of power is:

And the work-energy theorem states that:

Since the movement starts from rest, we have that:

And putting all together:

Since we want the time taken:

Which for our values is:

Gravity acts to accelerate the ball downward, and air resistance acts in a way to slow the ball along it's instantaneous velocity (no matter which way it's moving air applies a force in the opposite direction)
The molarity remains the same so the ratio does not change