Answer:
(a) 2.88×10⁻² W/m²
(b) 8.36×10⁻³ W/m²
Explanation:
The intensity of sound from an isotropic point source, with distance L is given as
I = P/(4πL²) .................................... Equation 1
Where I = intensity of sound, P = Power from the source, L = length, π = pie.
(a)
1.4 m from the source.
I = P/(4πL²)
Given: P = 0.71 W, L = 1.4 m, π = 3.14.
Substitute into equation 1
I = 0.71/(4×3.14×1.4²)
I = 0.71/24.6176
I = 0.0288 W/m².
I = 2.88×10⁻² W/m²
(b) 2.6 m from the source.
Given: P = 0.71 W, L = 2.6 m, π = 3.14
Substitute into equation 1
I = 0.71/(4×3.14×2.6²)
I = 0.71/84.9056
I = 0.00836 W/m²
I = 8.36×10⁻³ W/m²
Answer:
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.
Explanation:
eventually the crust cracks.
Answer:

Explanation:
According to Coulomb's law, the magnitude of the electric force between two equals charges (q) is given by:

Here k is the coulomb constant and d is the distance between the charges. For two electrons we have:

Answer:
The hydro static force on the back of the dam is 
Explanation:
Given that,
Width b= 1000 m
Depth d= 200 m
We need to calculate the average pressure
Using formula of average pressure

Put the value into the formula


We need to calculate the hydro static force on the back of the dam
Using formula of force

Put the value into the formula


Hence, The hydro static force on the back of the dam is 
The "i" component of a vector is in the x-direction. Therefore, the x-component is 3 m/s.