Answer:
7976 Pascals significant figure= 7.9*10^3
Explanation:
formula of hpg = height*density*gravitational energy 
.80*10*997=7976 pascals
 
        
             
        
        
        
Heat required to change the phase of ice is given by
Q = m* L
here 
m = mass of ice
L = latent heat of fusion
now we have
m = 45 kg
L = 334 KJ/kg
now by using above formula


In KJ we can convert this as

so the correct answer is D option
 
        
                    
             
        
        
        
Answer:
2. Wavelength 
Explanation:
When a photon collides with an electron and is deflected, the photon’s wavelength decreases.
When photon gained energy by the collision of the electron. Its energy and frequency will be increased and its wavelength will be decreased. 
 
        
                    
             
        
        
        
 The correct answer for this question is "Two-car length rule." While driving, the principle that you should be used to keep the appropriate distance between your vehicle and the vehicle in front of you is to follow the <span>Two-car length rule. This rule is to be followed for safety.</span>