The car has an initial velocity
of 23 m/s and a final velocity
of 0 m/s. Recall that for constant acceleration,
![v=v_0+at](https://tex.z-dn.net/?f=v%3Dv_0%2Bat)
The car stops in 7 s, so the acceleration is
![0\,\dfrac{\mathrm m}{\mathrm s}=23\,\dfrac{\mathrm m}{\mathrm s}+a(7\,\mathrm s)](https://tex.z-dn.net/?f=0%5C%2C%5Cdfrac%7B%5Cmathrm%20m%7D%7B%5Cmathrm%20s%7D%3D23%5C%2C%5Cdfrac%7B%5Cmathrm%20m%7D%7B%5Cmathrm%20s%7D%2Ba%287%5C%2C%5Cmathrm%20s%29)
![\implies a\approx-3.29\,\dfrac{\mathrm m}{\mathrm s^2}](https://tex.z-dn.net/?f=%5Cimplies%20a%5Capprox-3.29%5C%2C%5Cdfrac%7B%5Cmathrm%20m%7D%7B%5Cmathrm%20s%5E2%7D)
C. I took the test...........
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.
Sorry to say but I know that t(e introduction is first and the coda is last
Answer:
Magnitude of the magnetic field inside the solenoid near its centre is 1.293 x 10⁻³ T
Explanation:
Given;
number of turns of solenoid, N = 269 turn
length of the solenoid, L = 102 cm = 1.02 m
radius of the solenoid, r = 2.3 cm = 0.023 m
current in the solenoid, I = 3.9 A
Magnitude of the magnetic field inside the solenoid near its centre is calculated as;
![B = \frac{\mu_o NI}{l} \\\\](https://tex.z-dn.net/?f=B%20%3D%20%5Cfrac%7B%5Cmu_o%20NI%7D%7Bl%7D%20%5C%5C%5C%5C)
Where;
μ₀ is permeability of free space = 4π x 10⁻⁷ m/A
![B = \frac{4\pi*10^{-7} *269*3.9}{1.02} \\\\B = 1.293 *10^{-3} \ T](https://tex.z-dn.net/?f=B%20%3D%20%5Cfrac%7B4%5Cpi%2A10%5E%7B-7%7D%20%2A269%2A3.9%7D%7B1.02%7D%20%5C%5C%5C%5CB%20%3D%201.293%20%2A10%5E%7B-3%7D%20%5C%20T)
Therefore, magnitude of the magnetic field inside the solenoid near its centre is 1.293 x 10⁻³ T