Answer:
The length is 
Explanation:
From the question we are told that
The frequencies of the two successive harmonics are
, 
The speed of sound in the air is 
Generally the frequency of a given harmonic is mathematically represented as

Here n defines the position of the harmonics
Now since the position of both harmonic is not know but we know that they successive then we can represented them mathematically as

and

So

=> 
=> 
P.E = mgh
This is the formula for potential energy.
This is where m is mass, g is the acceleration due to gravity, and h is height.
All you have to do is multiply all these numbers together.
In 2Cr2O7 there’s 2 items; Cr and O
Answer:
Explanation:
If an object has a higher density than the fluid it is in (fluid can mean liquid or gas), it will sink. If it has a lower density, it will float. Density is determined by an object's mass and volume. If two objects take up the same volume, but have one has more mass, then it also has a higher density.