Answer:
compound
Explanation:
a substance made from two or more different elements that have been chemically joined. Examples of compounds include water (H2O), which is made from the elements hydrogen and oxygen, and table salt (NaCl), which is made from the elements sodium and chloride.
Answer:
Both are subject to a persons interpretation
Explanation:
We hear people describe this when somebody is making an irresistible sound. usually people say the baby has a pitch scream.
Answer:
Therefore,
The frequency heard by the engineer on train 1

Explanation:
Given:
Two trains on separate tracks move toward each other
For Train 1 Velocity of the observer,

For Train 2 Velocity of the Source,

Frequency of Source,

To Find:
Frequency of Observer,
(frequency heard by the engineer on train 1)
Solution:
Here we can use the Doppler effect equation to calculate both the velocity of the source
and observer
, the original frequency of the sound waves
and the observed frequency of the sound waves
,
The Equation is

Where,
v = velocity of sound in air = 343 m/s
Substituting the values we get

Therefore,
The frequency heard by the engineer on train 1


The apparent depth of an object at the bottom of a tank filled with a liquid of refractive index 1.3 is 7.7 cm. What is the actual depth of the liquid in the tank?

REFRACTIVE INDEX = 1.3
APPARENT DEPTH = 7.7 cm

REAL DEPTH OF THE OBJECT.



Refractive Index = 1.3
Apparent Depth = 7.7 cm
Putting the values in the formula:-

The main purpose of the turbine in the turbojet engine is to "<span>compress the air". There is also the added factor of pushing the air, which increases mobility. </span>