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:
New force, 
Explanation:
The electrostatic force between two spheres is given by :
According to given condition, each of the spheres has lost half its initial charge, new force is given by :
So, the new force becomes (1/4)th of the initial force. Hence, the correct option is (d).
Answer:
visible light
Explanation:
we can not see with out visibl e light
Answer:
Because the energy is waning
Explanation: hope this helps
All the colors of the visible spectrum
