Given that,
Distance, d = 10700 km
Time taken by the airplane to complete the destination, t = 12 hours
We need to find the speed of the airplane. It is equal to the total distance covered divided by total time taken. So,

We know that,
1 km = 1000 m
1 h = 3600 s
So,

So, the speed of the airplane is 891.66 km/h or 247.68 m/s.
The diagram is missing; however, we know that the intensity of a sound wave is inversely proportional to the square of the distance from the source:

where I is the intensity and r is the distance from the source.
We can assume for instance that the initial distance from the source is r=1 m, so that we put

The intensity at r=3 m will be

Therefore, the sound intensity has decreased by a factor

.
Answer:
3.135 kN/C
Explanation:
The electric field on the axis of a charged ring with radius R and distance z from the axis is E = qz/{4πε₀[√(z² + R²)]³}
Given that R = 58 cm = 0.58 m, z = 116 cm = 1.16m, q = total charge on ring = λl where λ = charge density on ring = 180 nC/m = 180 × 10⁻⁹ C/m and l = length of ring = 2πR. So q = λl = λ2πR = 180 × 10⁻⁹ C/m × 2π(0.58 m) = 208.8π × 10⁻⁹ C and ε₀ = permittivity of free space = 8.854 × 10⁻¹² F/m
So, E = qz/{4πε₀[√(z² + R²)]³}
E = 208.8π × 10⁻⁹ C × 1.16 m/{4π8.854 × 10⁻¹² F/m[√((1.16 m)² + (0.58 m)²)]³}
E = 242.208 × 10⁻⁹ Cm/{35.416 × 10⁻¹² F/m[√(1.3456 m² + 0.3364 m²)]³}
E = 242.208 × 10⁻⁹ Cm/35.416 × 10⁻¹² F/m[√(1.682 m²)]³}
E = 6.839 × 10³ Cm²/[1.297 m]³F
E = 6.839 × 10³ Cm²/2.182 m³F
E = 3.135 × 10³ V/m
E = 3.135 × 10³ N/C
E = 3.135 kN/C
Answer:
i 5.3 cm ii. 72 cm
Explanation:
i
We know upthrust on iron = weight of mercury displaced
To balance, the weight of iron = weight of mercury displaced . So
ρ₁V₁g = ρ₂V₂g
ρ₁V₁ = ρ₂V₂ where ρ₁ = density of iron = 7.2 g/cm³ and V₁ = volume of iron = 10³ cm³ and ρ₂ = density of mercury = 13.6 g/cm³ and V₂ = volume of mercury displaced = ?
V₂ = ρ₁V₁/ρ₂ = 7.2 g/cm³ × 10³ cm³/13.6 g/cm³ = 529.4 cm³
So, the height of iron above the mercury is h = V₂/area of base iron block
= 529.4 cm³/10² cm² = 5.294 cm ≅ 5.3 cm
ρ₁V₁g = ρ₂V₂g
ii
ρ₁V₁ = ρ₃V₃ where ρ₁ = density of iron = 7.2 g/cm³ and V₁ = volume of iron = 10³ cm³ and ρ₃ = density of water = 1 g/cm³ and V₃ = volume of water displaced = ?
V₃ = ρ₁V₁/ρ₃ = 7.2 g/cm³ × 10³ cm³/1 g/cm³ = 7200 cm³
So, the height of column of water is h = V₃/area of base iron block
= 7200 cm³/10² cm² = 72 cm
Neglecting friction and air resistance, the first hill must be built 4 times higher than it is now.