Answer:
A.
Explanation: both triple by 3
Answer:
D
Explanation:
If you list and compare, the elephants hearing range is the closest to a humans.
Humans: 20-20,000
Elephant: 16-12,000
While the others are either too much more or less than a humans.
Bat: 2,000-110,000
Dolphin: 90-105,000
Chicken: 125-2,000
Answer:
Milk
Explanation:
It can be milk and other foods similar to milk like ice cream, cheese, yogurt, etc. This is why people say milk is good for your bones cause it has calcium
Answer:
Today, scientists believe that the main reason the earth has had periodic ages is that the climate of earth is controlled by the difference in heating of it's surface by the sun. As for example, the equatorial regions are the warmest as the sun is vertically overhead of those areas and the polar regions where the sun is at the extreme angels are the coldest ones.
Explanation:
Answer:
v ’= 21.44 m / s
Explanation:
This is a doppler effect exercise that changes the frequency of the sound due to the relative movement of the source and the observer, the expression that describes the phenomenon for body approaching s
f ’= f (v + v₀) / (v-
)
where it goes is the speed of sound 343 m / s, v_{s} the speed of the source v or the speed of the observer
in this exercise both the source and the observer are moving, we will assume that both have the same speed,
v₀ = v_{s} = v ’
we substitute
f ’= f (v + v’) / (v - v ’)
f ’/ f (v-v’) = v + v ’
v (f ’/ f -1) = v’ (1 + f ’/ f)
v ’= (f’ / f-1) / (1 + f ’/ f) v
v ’= (f’-f) / (f + f’) v
let's calculate
v ’= (3400 -3000) / (3000 +3400) 343
v ’= 400/6400 343
v ’= 21.44 m / s