Answer:
  F = 5226.6 N
Explanation:
To solve a lever, the rotational equilibrium relation must be used.
We place the reference system on the fulcrum (pivot point) and assume that the positive direction is counterclockwise
          F d₁ = W d₂
where F is the applied force, W is the weight to be lifted, d₁ and d₂ are the distances from the fulcrum.
In this case the length of the lever is L = 5m, t the distance desired by the fulcrum from the weight to be lifted is
d₂ = 200 cm = 2 m
therefore the distance to the applied force is
           d₁ = L -d₂
          d₁ = 5 -2
          d₁= 3m
we clear from the equation
           F = W d₂ / d₁
           W = m g
           F = m g d₂ / d₁
 we calculate
       F = 800 9.8 2/3
       F = 5226.6 N
 
        
             
        
        
        
That's false.  Mechanical waves (like sound and ocean waves) do
need a medium to travel in, but electromagnetic waves (like radio 
and light) don't. 
        
                    
             
        
        
        
Choice-B is the correct one.  
-- The atomic number is the number of protons in the nucleus.
-- Each proton in the nucleus is usually matched by one electron in the 'cloud'.
-- The addition of a proton OR a neutron increases the mass number by 1 .
-- Electrons have such small mass that they don't figure into the atomic mass at all.
        
             
        
        
        
A is right because I took the test
        
             
        
        
        
Answer: An object undergoing uniform circular motion is moving 
Explanation: