Answer:
the angle of incidence θ is 45.56 º
Explanation:
Given data
strikes the mirror before wall x = 30.7 cm
reflected ray strikes the wall y = 30.1 cm
to find out
the angle of incidence θ
solution
let us consider ray is strike at angle θ so after strike on surface ray strike to wall at angle 90 - θ
we will apply here right angle triangle rule that is
tan( 90 - θ) = y /x
tan( 90 - θ) = 30.1 / 30.7
90 - θ = tan^-1 (30.1/30.7)
90 - θ = 44.4345
θ = 45.56 º
the angle of incidence θ is 45.56 º
Answer: A.E.
Explanation: To understand the distinction between mass and weight and to be able to calculate the weight of an object from its mass and Newton's law of gravitation. The concepts of mass and weight are often confused. In fact, in everyday conversations, the word "weight" often replaces "mass," as in "My weight is seventy-five kilograms"
The reciprocal of the total resistance is equal to the sum of the reciprocals of the component resistances:
1/(120.7 Ω) = 1/<em>R₁</em> + 1/(221.0 Ω)
1/<em>R₁</em> = 1/(120.7 Ω) - 1/(221.0 Ω)
<em>R₁</em> = 1 / (1/(120.7 Ω) - 1/(221.0 Ω)) ≈ 265.9 Ω
Answer:
time=4s
Explanation:
we know that in a RL circuit with a resistance R, an inductance L and a battery of emf E, the current (i) will vary in following fashion
, where 
max=
Given that, at i(2)=
⇒
⇒
⇒
Applying logarithm on both sides,
⇒
⇒
⇒
Now substitute 
⇒
⇒
⇒
Applying logarithm on both sides,
⇒
⇒
⇒
now subs.
⇒
also 
⇒
⇒
