Please I need help on this
1 answer:
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Answer:
A) The set builder notation is: {n | n∈Z, 1≤n≤7}.
B) The set builder notation is:
C) The set builder notation is:
D) The set builder notation can be:
Step-by-step explanation:
Consider the provided information,
We need to use set-builder notation to describe the following sets.
(a) {1,2,3,4,5,6,7}
Here, the number are integer starting from 1 to 7.
Thus, the set builder notation is: {n | n∈Z, 1≤n≤7}.
(b) {1, 10, 100, 1000, 10000}
The above set can be written as:
Thus, the set builder notation is:
(c) {1, 1/2, 1/3, 1/4, 1/5, ...}
Here the numerator is 1 for each term but denominator is natural number.
Thus, the set builder notation is:
(d) {0}
The set builder notation can be:
Answer:
150.51 dB
Step-by-step explanation:
Data provided in the question:
decibel level of sound at 161 km distance = 180 dB
d₁ = 161 km
d₂ = 4800 km
I₁ = 180 db
The formula for intensity of sound is given as:
I =
and the relation between intensity and distance is given as:
I ∝
or
Id² = constant
thus,
I₁d₁² = I₂d₂²
or
therefore,
I =
or
I =
or
I = 20 × (-1.474)
or
I = -29.49
Therefore,
the decibel level on Rodriguez Island, 4,800 km away
= 180 - 29.49
= 150.51 dB