From the information given, cannon ball weighs 40 kg and has a potential energy of 14000 J.
 We need to find its height.
We will use the formula P.E = mgh
Therefore h = P.E / mg
where P.E is the potential energy,
 m is mass in kg,  
g is acceleration due to gravity (9.8 m/s²)
 h is the height of the object's displacement in meters.
h = P.E. / mg
h = 14000 / 40 × 9.8
h = 14000 / 392
h = 35.7
Therefore the canon ball was 35.7 meters  high.
 
        
             
        
        
        
The common value for “Speed of light in vacuum” is  metre per second.
  metre per second.
Answer: Option b
<u>Solution:
</u>
Speed of light can be defined as the speed with which light waves propagate in different medium. In vacuum, speed of light is 186,282 miles per second or 299,792 km/s which is rounded off as  .
.
“Speed of light in vacuum” is a universal constant and usually represented by ‘c’. Light waves travels at a speed of  metre per second in vacuum.
  metre per second in vacuum.
 
        
             
        
        
        
They emit low leavls of carbon dioxide (CO2) and the emissions of green house gases and therefore the contribution of nuclear power plants to global warming is therefore pretty little
 
        
                    
             
        
        
        
Protons have a positive charge