Answer:
The value is 
Explanation:
From the question we are told that
The power rating of the stove is 
The duration of its use everyday is 
The rating of the light bulbs is 
The number is 
The power rating of the total bulb is 
The duration of its use everyday is 
The power rating of miscellaneous appliance 
The duration of its use everyday is 
The power rating of hot water 
The duration of its use everyday is 
Generally the total electrical energy used in 1 month is mathematically represented as
=> 
=> 
=> 
Generally the monthly electricity bill is mathematically represented as
=>
The process of formation of a reddish-brown substance on the surface of the iron objects in the presence of flaky moisture and air is called rusting.
<span>A. How could energy become the matter present today? </span>
Answer: critical angle, sin^-1 (n2/n1)
Explanation: the angle of incidence at which the retracted ray makes an angle of 90° with the normal is known as the critical angle.
Snell's law defined refraction mathematically as shown below
n1 sin θi = n2 sin θr
n1 = refractive index of the first medium
n2 = refractive index of the second medium
θi = angle of incidence
θr = angle of refraction
When the refrafted ray is perpendicular to the normal, the angle of refraction (θr) is 90° hence making the angle of incidence (θi) the critical angle θc
By substituting these conditions into the Snell's law, we have that
n1 sin θc = n2 sin 90
According to trigonometry, the value of sin 90 is 1, hence we have that
n1 sin θc =n2
sin θc = n2/n1
θc = sin^-1 (n2/n1)
