4 to 1
Explanation If you look at it as a fraction 160/40 and you reduce it down as far as you can you get 4/1
Heat lost or gained, H = mc(θ₂ - θ₁)
Where m = mass, c = Specific heat capacity, θ₂= final temperature, θ₁ = initial temperature
m = 200g, c = 0.444 J/g°C, θ₁ = 22 °C (Since it was cooled).
H = 6.9 kj = 6.9 *1000J = 6900 J
6900 = 200*0.444* (θ₂ - 22)
6900/(200*0.444) = θ₂ - 22
77.70 = θ₂ - 22
θ₂ - 22 = 77.7
θ₂ = 77.7 + 22 = 99.7
So initial temperature before cooling ≈ 100°C . Option C.
Answer:
Because the velocity v (As a Vector ) is going opposite direction ( -X axis ) .
Newton’s Thrid Law, which states that for every reaction there is an opposite reaction.
Refractive Index is a ratio of two similar physical quantity which is dimension less
refractive index = sin I / sin r
therefore it doesn't have a unit.
