<h2>
Answer: an underground lake</h2>
Explanation:
In general, sound (mechanical waves) travels faster in solids than in liquids, and faster in liquids than in gases. This is because <u>the speed of the mechanical waves is determined by a relationship between the elastic properties of the medium </u>in which they are propagated and the mass per unit volume of the medium (that is:<u>density</u>).
In other words: The speed of sound varies depending on the medium through which the sound waves travel.
So, if we are told the sound wave initially had a speed of 4,000 m/s and it suddenly decreases to 1,500 m/s, this means the sound waves passed from a solid medium to a liquid medium.
Hence, the correct option is: an underground lake.
Answer:
Time period of the osculation will be 2.1371 sec
Explanation:
We have given mass m = (B+25)
And the spring is stretched by (8.5 A )
Here A = 13 and B = 427
So mass m = 427+25 = 452 gram = 0.452 kg
Spring stretched x= 8.5×13 = 110.5 cm
As there is additional streching of spring by 3 cm
So new x = 110.5+3 = 113.5 = 1.135 m
Now we know that force is given by F = mg
And we also know that F = Kx
So 

Now we know that 
So 


Answer:

Explanation:
<u>Density
</u>
The density of a substance is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:

We have a cube-shaped piece of copper of 4 cm of side length. The volume of the piece is:

Surprisingly, no other magnitude is required, thus the answer is:

I think it’s D-decreases the amount of work.
The sphere’s Electric potential energy is 1.6*
J
Given,
q=6. 5 µc, V=240 v,
We know that sphere’s Electric potential energy(E) = qV=6.5*
=1.6*
J
<h3>Electric potential energy</h3>
The configuration of a certain set of point charges within a given system is connected with the potential energy (measured in joules) known as electric potential energy, which is a product of conservative Coulomb forces. Two crucial factors—its inherent electric charge and its position in relation to other electrically charged objects—can determine whether an object has electric potential energy.
In systems with time-varying electric fields, the potential energy is referred to as "electric potential energy," but in systems with time-invariant electric fields, the potential energy is referred to as "electrostatic potential energy."
A tiny sphere carrying a charge of 6. 5 µc sits in an electric field, at a point where the electric potential is 240 v. what is the sphere’s potential energy?
Learn more about Electric potential energy here:
brainly.com/question/24284560
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