Answer: Identical rays are refracted upon entering
Explanation:
Answer:
The initial arrow's velocity is 40,9 m/s at 11.9° from the horizontal
Explanation:
<em>In order to find the inital velocity we need to determine its components and the angle that the arrow is launched at.</em>
<em>For horizontal component, we will have:</em>
<em>ν cos(θ)t = x ⇒ cos(θ) = x/νt</em>
<em>For vertical component we will have:</em>
<em>h= v sin(θ)t ₋ gt²÷ 2 ⇒ sin (θ) = h + gt²÷2/νt</em>
<em>From the two equations we got, after noting that the vertical displacement is 3m, we can calculate </em>
<em>tan(θ) = h +gt²÷2/νt/ x÷νt = h+ gt²÷2/x = 3+ 9.8.0.5²÷2/20 = 0.21125</em>
<em>Now we can calculate θ = tan⁻¹(0.21125) ≈ 11.9°</em>
<em>Now that we know the angle we can subtitute at any of the expressions for the two components of the velocity . Let's do this subsitution at the horizontal component:</em>
<em>ν cos(θ)t= x =ν = x/tcos(θ)= 20/ 0.5cos(11.9) ≈ 40.9 m/s.</em>
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The answer is B. The atmosphere provides the earth a moderate and livable climate. The atmosphere is a storage of gases. It contains air which has oxygen that enables us to breath and live in this planet. Also, the atmosphere protects the people by absorbing harmful electromagnetic radiation from the sun.
The correct answer to the question is : 
EXPLANATION :
As per the question, the specific heat of gold is given as c = 
The heat given to the gold dQ = 195 J
The mass of the gold is given as m = 15 gram.
We are asked to calculate the change in temperature.
Let the change in temperature is dT.
We know that dQ = mcdT
[ANS]
Hence, the change in temperature is 100 degree celsius.
Use pythagorean theorem
to find the opposite side, which is 7.3
so then you can just use inverse sinA=7.3/10 which equals 46.9 degrees
