Answer:
I. They come from sources across space
II. They travel in a straight line from their source.
III. They can be reflected by some types of material.
Explanation:
Light wave can be defined as an electromagnetic wave that do not require a medium of propagation for it to travel through a vacuum of space where no particles exist.
The following statements about light waves are true;
I. They come from sources across space.
II. They travel in a straight line from their source.
III. They can be reflected by some types of material. reflection occurs when a ray of light or wavefronts bounces off a smooth surface. Thus, when light hit a surface, it bounces back to the medium from which it was originally propagated with.
However, light waves cannot travel through all type of material except materials that are transparent or translucent but not opaque.
Answer:
Explanation:
From the question we are told that:
Distance of wall from CD 
Second bright fringe 
Let
Strontium vapor laser has a wavelength \lambda= 431 nm=>431 *10^{-9}m
Generally the equation for Interference is mathematically given by
Where
Answer:
15 because 5×5×5 is the same thing as 5×3 which equals to 15
1.5 m/s is the velocity.
9.3 m is the length of aisle, over which Distance will be covered.
Time is demanded in which the child will move the cart over the aisle with 1.5 m/s.
v=S/t
and,
t=S/v
Put values,
t=9.3/1.5=6.2 s
