The light collected by a telescope is proportional to the area of the telescope.
The area of a telescope is π * (Diameter / 2) ^2 = π * (Diameter)^2 / 4.
So, for the 20.0 cm telescope, area = π * (20.0cm)^2 / 4.
And for the 5.0 cm telescope, area = π * (5.0 cm)^2 / 4
So, divide both expressions to find the ratio of collection of light of one telescope to the other:=> (20.0)^2 / (5.0)^2 = (20.0 / 5.0)^2 = 4^2 = 16
Then, the 20.0 cm telescope collects 16 times the ligth that the 5.0 cm telescope collect. <--- answer
Answer:
At the same time.
Explanation:
In the first case ,
intial velocity = 0
displacement = -h
acceleration = -g
Using second equation of motion,
s = ut + .5a
- h = - 0.5g
t = 
In the second case, consider only motion along y axis,
intial velocity = 0 ( all the velocity is along x axis)
displacement = -h ( height is same in both cases)
acceleration = -g
Using second equation of motion,
s = ut + .5a
- h = - 0.5g
t = 
In both cases time is same.
Hence, they will reach the ground simultaneously.
Answer:

Explanation:
As per Ampere's law the magnetic field at the surface of the wire is given as

here we have

so we will have

now again we use same value of current but wire with double the diameter
so the magnetic field at the surface is given as

so we have

James braid came up with the term hypnosis