Answer:
75.6J
Explanation:
Hi!
To solve this problem we must use the first law of thermodynamics that states that the heat required to heat the air is the difference between the energy levels of the air when it enters and when it leaves the body,
Given the above we have the following equation.
Q=(m)(h2)-(m)(h1)
where
m=mass=1.3×10−3kg.
h2= entalpy at 37C
h1= entalpy at -20C
Q=m(h2-h1)
remember that the enthalpy differences for the air can approximate the specific heat multiplied by the temperature difference
Q=mCp(T2-T1)
Cp= specific heat of air = 1020 J/kg⋅K
Q=(1.3×10−3)(1020)(37-(-20))=75.6J
Answer:
charge Qint = 7.17 10⁻⁴ C
Explanation:
For this problem we must use Gauss's law
F = ∫ E. dA = Qint / εₙ
let's form a Gaussian surface that is parallel to the surface, for example, a Cube. As the field is vertical and perpendicular to the surface, the field lines and the area vector are parallel whereby the scalar product is reduced to an ordinary product.
Φ = E A = Qint / ε₀
A = 1 km² (1000 m / 1km)² = 1 10⁶ m²
We can calculate the charge
Qint = E A ε₀
Qint = 81 1 10⁶ 8.85 10⁻¹²
Qint = 7.17 10⁻⁴ C
Displacement is known as the net movement of an object with respect to its original position. One may travel out of his city and return. Despite having covered many miles, he will have have a displacement of 0.
This is true for all paths that have zero displacement, that they all return to their original position.
Answer:
0.056 miles away
Explanation:
From sound wave,
v = 2x/t .................................. Equation 1
Where v = velocity of sound in air, x = distance of echo, t = time.
making x the subject of the equation,
x = 2v/t........................... Equation 2.
Given: v = 344 m/s, t = 7.6 s.
Substituting into equation 2
x = 2(344)/7.6
x = 90.53 m.
x = 90.53/1609.344
x = 0.056 mile.
Thus the lighting strike 0.056 miles away
