Answer: 3.84dB
Explanation:
Since person A is talking 1.2dB louder than B, we will have
A = 1.2B... (1)
Similarly, person C is talking 3.2 dB louder than person A, we have
C = 3.2A... (2)
From equation 1, B = A/1.2... (3)
To get the ratio of the sound intensity of person C to the sound intensity of person B, we will divide equation 2 by 3 to give
C/B = 3.2A/{A/1.2}
C/B = 3.2A×1.2/A
C/B = 3.2×1.2
C/B = 3.84dB
<span>4) Formation of a gas
When methane burns, it produces the gases water vapor and carbon dioxide.
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Answer:
The height of the image is, h' = 6.0 cm
The image is erect.
Explanation:
Given data,
The object distance, u = -5 cm
The focal length of convex lens, f = 10 cm
The object height, h = 3 cm
The lens formula,



v = -10 cm
The magnification factor of lens

m = 2



h' = 6 cm
The height of the image is, h' = 6 cm
The image is erect.
Answer:
the speed of the satellite is 12,880.53 km/h
Explanation:
Given;
radius of the circular orbit, r = 24,600 km
time taken to revolve around Earth, t = 12 hours
The circumference of the satellite is calculated as;
L = 2πr
L = 2π x 24,600 km
L = 49,200π km
L = 154,566.36 km
The speed of the satellite;
v = L/t
v = 154,566.36 / 12
v = 12,880.53 km/h
Therefore, the speed of the satellite is 12,880.53 km/h