Answer:
121.0 W
Explanation:
We use the equation for rate of heat transfer during radiation.
Q/t = σεA(T₂⁴ - T₁⁴)
Since temperature of surroundings = T₁ = -20.0°C = 273 +(-20) = 253 K, and temperature of skier's clothes = T₂ = 5.50°C = 273 + 5.50 = 278.5 K.
Surface area of skier , A = 1.60 m², emissivity of skier's clothes, ε = 0.70 and σ = 5.67 × 10⁻⁸ W/m²K⁴
.
Therefore, the rate of heat transfer by radiation Q/t is
Q/t = σεA(T₂⁴ - T₁⁴) = (5.67 × 10⁻⁸ W/m²K⁴
) × 0.70 × 1.60 m² × (278.5⁴ - 253⁴) = 6.3054 × (1918750544.0625) × 10⁻⁸ W = 1.2098 × 10² W = 120.98 W ≅ 121.0 W
One of the efficient concepts that can help us find the number of turns of the cable is through the concept of induced voltage or electromotive force given by Faraday's law. The electromotive force or emf can be described as,
Where,
N = Number of loops
B = Magnetic Field
A = Cross-sectional Area
= Angular velocity
Re-arrange to find N,
Our values are given as,
Replacing at our equation we have:
Therefore the number of loops of wire should be wound on the square armature is 32 loops
Answer:
Compare brands first, but purchase the one that has lots of commercial advertisements, Compare ingredients and purchase the brand that is safe to use with soft contact lenses, Compare prices and purchase the most inexpensive brand.
Explanation:
