1. a. longitudinal waves.
There are two types of waves:
- Transverse waves: in transverse waves, the oscillations of the wave occur in a direction perpendicular to the direction of propagation of the wave
- Longitudinal waves: in longitudinal waves, the oscillations of the waves occur parallel to the direction in which the waves are travelling.
So, these types of waves are called longitudinal waves.
2. d. a medium
There are two types of waves:
- Electromagnetic waves: these waves are produced by the oscillations of electric and magnetic field, and they can travel both in a medium and also in a vacuum (they do not need a medium to propagate)
- Mechanical waves: these waves are produced by the oscillations of the particles in a medium, so they need a medium to propagate - therefore, the correct choice is d. a medium
3. a. AM/FM radio
Analogue signals consist of continuous signals, which vary in a continuous range of values. On the contrary, digital signals consist of discrete signals, which can assume only some discrete values. For AM and FM radios, signals are transmitted by using analogue signals.
Answer: B. The gravitational field strength of Planet X is Wx/m.
Explanation:
Weight is a force, and as we know by the second Newton's law:
F = m*a
Force equals mass times acceleration.
Then if the weight is:
Wx, and the mass is m, we have the equation:
Wx = m*a
Where in this case, a is the gravitational field strength.
Then, isolating a in that equation we get:
Wx/m = a
Then the correct option is:
B. The gravitational field strength of Planet X is Wx/m.
Answer:

Explanation:
Given:
- volume of oil in the cylinder,

- volume of the oil level when the ice is immersed,

- the volume level of oil when the ice melted,

<u>Now, therefore the volume of ice:</u>



<u>Now the volume of water:</u>



As we know that the relative density is the ratio of density of the substance to the density of water.
<u>So, the relative density of ice:</u>
.....................(1)
as we know that density is given as:

now eq. (1)

where, m = mass of the water or the ice which remains constant in any phase



<span>The minimum energy required for isomerization is 267 000 J/mol
</span>
The isomerization of cis-but-2-ene to trans-but-2-ene requires breaking of the π bond.
The bond energy of a C-C σ bond is 347 kJ/mol.
The bond energy of a C=C double bond (σ + π) is 614 kJ/mol.
So the bond energy of a π bond is (614 – 347) kJ/mol = 267 kJ/mol =
267 000 J/mol.
Answer:
Explained
Explanation:
Two pieces of the same metal can have different recrystallization temperatures if the pieces have been cold worked to different amounts. The piece of work cold worked to greater extend will have more internal energy to drive the recrystalline process and lower recrystallization temperature.
Yes, its possible that recrystallization to take place in some regions of a part before it does in other regions of the same part if the work has been unevenly strained or if the part have different thickness at different sections.