Answer: Physical changes only change the appearance of a substance, not its chemical composition. Chemical changes cause a substance to change into an entirely substance with a new chemical formula. Chemical changes are also known as chemical reactions.
Explanation:
Answer:
Electromagnetic induction
Explanation:
The process of generating electric current with a magnetic field. It occurs whenever a magnetic field and an electric conductor move relative to one another so the conductor crosses lines of force in the magnetic field.
It depends on the direction in which the shell is launched. The time can be anything from 3.6 seconds to never.
Answer:
a

b

Explanation:
From the question we are told that
Their distance apart is 
The wavelength of each source wave 
Let the distance from source A where the construct interference occurred be z
Generally the path difference for constructive interference is

Now given that we are considering just the straight line (i.e points along the line connecting the two sources ) then the order of the maxima m = 0
so

=> 
=> 
Generally the path difference for destructive interference is

=> 
=> 
substituting values

=> 
So


and

=> 
=> 
'N' is labelled 'runoff'. That's when the water is down. Streets are wet, worms come out of the ground, and water flows down the street to the sewer.