BRAINLIEST. Agraph is probelow. The graph shows the speed of a car traveling east over a 12 second period. Based on the informat
ion in the graph, it can be
that in the first second
that in the first second
2 answers:
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ANSWER:100dB
f<em>rom the sound intensity level,the sound intensity is calculated as:</em>
<em /><em>₁=</em>
<em>=(10dB)㏒₁₀(l₁/l₀)</em>
<em>inserting numbers:</em>
<em>120dB=(10dB)㏒₁₀[l₁/10⁻¹²W/m⁸] or 12=㏒₁₀[l₁/(10⁻¹²)W/m²</em>
<em>Getting the antilog of both sides and obtain 10¹²=l₁(10⁻¹²W/m²)which </em>
<em>can be used to solve for l₁ and get</em>
<em> l₁=(10⁻¹²W/m²)(10¹²)=1 W/m²</em>
<em>since the sound intensity is related to the power and that the power does not change,the sound intensity at any other point can be solved.Plugging-in</em>
<em>ᵃ = 4πr²,into P=l₁ₐ₁=l₂ₐ₂ and get:</em>
<em>l₂=l₁(r₁/r₂)² =(1W/m²)(5/35) =2.04×10⁻²W/m²</em>
<em>since we know the sound intensity at the sound point 2r,the sound intensity level at the point can be solved.We have:</em>
<em> </em><em>₂=</em>
<em>=(10dB)㏒₁₀(l₂/l₀)=(10dB)㏒₁₀(2.04×10⁻²/1×10⁻²)</em>
<em> </em><em>₂=(10dB)㏒₁₀(2.04×10¹⁰)</em>
<em /><em> =(10dB)[㏒₁₀(2.04)+㏒₁₀(10¹⁰)]=10dB[0.32+10]=103dB=100dB</em>
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1) a) attract
The magnetic force between two magnetic poles is attractive for two unlike poles and repulsive for two like poles. Therefore we have:
1- For two north poles, the force between them is repulsive
2- For two south poles, the force between them is repulsive
3- For a north pole and a south pole, the force between them is attractive
In this problem, we are in the situation described in 3), so the force between the poles is attractive.
2) a) motion of electrons
While electric fields are produced by static electric charges, magnetic fields are produced by charges in motion (currents). In particular, a current in a wire (where a current is simply the motion of electrons inside the wire) produces a magnetic field whose intensity is
where
I is the current in the wire
r is the radial distance from the wire
And the direction of the field lines are such that the field form concentric circles around the wire.