X
Hot air rises = it's less dense than cold air = falls
 
        
                    
             
        
        
        
Answer:
It would be a physical change because you aren't changing to chemical properties of the glass, just the shape.
 
        
             
        
        
        
Answer:
A mineral is a valuable form of ore that can be extracted from the ground
Explanation:
Gold, quartz and talc are minerals because they are found in the earth in a valuable form of ore while ores are rocks that contain valuable concentrations of minerals.that can be mined.
An ORE in general term can be said to be a mineral deposit that contains enough Minerals that can be mined in commercial quantities while Minerals are valuable components of an Ore that can be mined ( naturally occurring ) in an ORE.
 
        
             
        
        
        
Answer:
 All the given option is false.
Explanation:
A)
This is not true for all the materials like composite because the Poisson ratio for composite material can be negative that is why positive tensile stress may produce positive lateral strain.
B)
This is not true for all the material because the Poisson ratio for some material can be positive  that is why positive tensile stress may produce negative lateral strain.
C)
The explanation is same as option A.
D)
This is not true for all the materials ,It is valid only up to elastic limit .After the elastic limit the strain and stress does not follow linear path.
E)
This is not true for all the materials because some materials like composite is having negative value of Young's modulus.
Therefore all the given option is false.
 
        
             
        
        
        
Answer:
The wavelength of the EM wave is 7.5 * 10⁻⁴ m
Explanation:
The velocity of a wave is related to its wavelength by the following formula;
velocity = wavelength * frequency
For an electromagnetic (EM) wave, its velocity is equal to the velocity of light, c = 3.0 * 10⁸ m/s
Given that the frequency and veloity of the given EM wave in the question is known, its wavelength is calculated as follows:
wavelength = velocity/frequency
where velocity of the EM wave = 3.0 * 10⁸ m/s;
frequency = 4THz = 4 * 10¹² Hz
wavelength = 3.0 * 10⁸m/s / 4 * 10¹² Hz
wavelength = 7.5 * 10⁻⁴ m
Therefore, the wavelength of the EM wave is 7.5 * 10⁻⁴ m