Two or more velocities add by vector addition
        
             
        
        
        
Answer:
 As the temperature increases, the kinetic energy of the particles increases.
Explanation:
When the temperature of the substance increases, the velocity increases which makes the movement of the particles to speed up. This causes the particles to increase. Therefore, as the temperature increases, the kinetic energy of the particles also increases.
 
        
                    
             
        
        
        
Answer:
The modern instruments or we can say the different levels of telescopes are used to explore and study the distant galaxies. i.e the Hubble telescope is out there providing the data regarding the different properties of the celestial entities which in other case is not visible to the human naked eye.
Explanation:
- Scientists and research workers are in constant search for more answers as they explore the universe and implement the laws of physics on the celestial entities. But, most of the objects inside the universe are not visible to human naked eye, as they are far from sight and thus more advanced form of instruments like the x-ray, optical, and light telescopes are used to determine the different properties of the celestial entities inside the universe. 
- As, these telescopes includes the most recent "Hubble telescope", which is out there inside the space to explore the universe and more over the galaxies by subjecting them with x-rays and then provide us with a very rough but valid results to study the distant galaxies. 
 
        
             
        
        
        
work is force x distance = 25 x 0.4
= 2.5x4 = 10joules
pwer would be 10j/2s watts .... 5 watts
 
        
             
        
        
        
Answer:
As light travels in a straight line at a constant speed, it's acceleration is <u>0 m/s²</u>.
There is no rate of change of speed, so there is no acceleration.
- <u>0 m/s²</u> is the right answer.