Rocks, earth aging, fossils
        
             
        
        
        
Answer:
0 J
Explanation:
given,
mass of the ball = 5 kg
radius of the horizontal circle = 0.5 m
tension in the string = 10 N
Work done = ?
Work done by the tension in the circular path will be equal to zero.
This is because body moves in circular path, the centripetal force act along the radius of the circle and motion is right angle to the tension on the string.
so, work done = F s cos θ
      θ = 90°,
work done = F s cos 90°        ∵ cos 90° = 0
Work done = 0 J
 
        
             
        
        
        
Actually it's 

 and it says that the energy of an object (E) is equal to the mass (m) of the object multiplied with the squared speed of light (

). This theory says that mass can be turned into energy and energy can be turned into mass. This is one of Einstein's theory of relativity.
 
        
        
        
V = 8 * 10^2 km/h = 800km/h
S= 1,8* 10^3 km = 1800km
t = ?
v = S/t
t = S/v
t = 1800km/ 800km/h
t ≈ 2,25h (135min)
        
             
        
        
        
Fluorine has nine protons