<span>the answer is energy is not created nor destroyed, but it can change from one energy form to another.</span>
10.00 °C this is the right answer need more question feel free to post
Answer:
V = 20 miles /sec
Explanation:
We have remaining distance = d = 96 miles
Lets call Pascal velocity V in miles per hour
Now if he increases his velocity by 50 % (equivalent to multiply by 1.5 ) he will need a time t₁ to arrive then as V = d/t
1.5* V = d/ t₁ ⇒ 1.5 * V = 96 /t₁
And in the case of reducing his velocity
(V / 4) = d/ (t₁ + 16 ) ⇒ V * (t₁ + 16 ) = 4*d ⇒ V*t₁ + 16*V = 384
So we a 2 equation system with two uknown variables
1.5*V = 96/t₁ (1)
V*t₁ + 16*V = 384 (2)
We solve from equation (1) t₁ = 64/V
And by substitution in equation (2)
V * (64/V) + 16* V = 384
64 + 16 *V = 384 ⇒ 16*V = 320 ⇒ V= 320/16
V = 20 miles /sec
Answer:
iv) It is 9x bigger than before
Explanation:
As the amplitudes of the new speakers add directly with the original one, taking into account the phase that they have, the composed amplitude of the sound wave is as follows:
At = A + 4A -2A = 3 A
The intensity of the wave, assuming it propagates evenly in all directions, is constant at a given distance from the source, and can be expressed as follows:
I = P/A
where P= Power of the wave source, A= Area (for a point source, is equal to the surface area of a sphere of radius r, where is r is the distance to the source along a straight line)
For a sinusoidal wave, the power is proportional to the square of the amplitude, so the intensity is proportional to the square of the amplitude also.
If the amplitude changes increasing three times, the change in intensity will be proportional to the square of the change in amplitude, i.e., it will be 9 times bigger.
So, the statement iv) is the right one.
Convex mirrors only produce virtual images
