Answer:
the noise level of 5400 flies is equal to 84.32 dB
Explanation:
Noise made by house flies = 47 dB from the distance of 2.4 m
to calculate the noise of 5400 flies at a distance of 2.4 m.
the intensity of noise
now, I' = 5400 I₀
= 
= ![10 [log_{10}[5400] +log_{10}(\dfrac{I}{I_0}))](https://tex.z-dn.net/?f=10%20%5Blog_%7B10%7D%5B5400%5D%20%2Blog_%7B10%7D%28%5Cdfrac%7BI%7D%7BI_0%7D%29%29)
= 10 ( 3.732 + 4.7 )
= 84.32 dB
hence, the noise level of 5400 flies is equal to 84.32 dB
Explanation:
This is simple.
Convert the speed of 45km/h to metres per second (m/s):
45 * 1000m = 45000m per hour.
1 hour = 60 seconds * 60 minutes = 3600 seconds.
45000m/h / 3600 = 12.5m/s
(A quicker way is just to divide by 3.6)
So in 20 seconds it would cover:
12.5m/s * 20s = 250m.
A car travelling at 45km/h would travel 250 metres in 20s.
Answer: 60m/s
Explanation:
The wavespeed is the distance covered by the wave in one second. It is measured in metre per second, and represented by the symbol V
Wavespeed (V) = Frequency F x wavelength λ
i.e V = F λ
In the first case:
Wavespeed = 30 m/s
Frequency of sound = 6Hz
Wavelength = 5m
In the second case:
Wavespeed = ?
Frequency of sound = (2x 6Hz = 12Hz)
Wavelength = 5m (remains constant)
Apply V = F λ
Wavespeed = 12 Hz x 5m
Wavespeed = 60m/s
Therefore, when frequency is doubled, the speed is also doubled. Thus, the new speed of the wave is 60m/s
The ball can't reach the speed of 20 m/s in two seconds, unless you THROW it down from the window with a little bit of initial speed. If you just drop it, then the highest speed it can have after two seconds is 19.6 m/s .
If an object starts from rest and its speed after 2 seconds is 20 m/s, then its acceleration is 20/2 = 10 m/s^2 .
(Gravity on Earth is only 9.8 m/s^2.)
<u>For the first question we use point-slope form of an equation</u>
y-
=m(x-
)
y=m(x-
)+
then we plug in the known values
y=m(x-4)+7
we leave the slope as variable m since it is undefined
<u>For Question 2
</u>
A line that is parallel to the x-axis is a horizontal line and since the slope of a line is defined as the Δy/Δx (change in y/change in x) and the change in y is 0 at any 2 points observed on the line the slope is 0. (0/any number is 0)
<u>For Question 3
</u>
Following the same relationship as question 2 we can solve for the slope.
Δy/Δx
-
/
-
now we plug in the known values from the two points given
(5-7)/(-3-1)
-2/-4
m=1/2 or 0.5
<u><em>and For the Final Question</em></u>
a translation left or right is done by affecting the x variable if you add 2 to x then the x value will have to be 2 less to get the same result...in other words when x is 1 the value of y is also 1...but if I wanted the whole equation translated left 2 unites then I would want the same y-value at an x-value 2 smaller... in other words, in our example x will be -1 when y is 1. For this value found on the graph to match the equation our x value must have 2 added to it in the equation....therefore the equation that translates y=|x| two units left is...
y=|x+2|
