Answer: vf= 51 m/s and d= 112 m
Explanation: solution attached
 
        
             
        
        
        
B is the answer because it takes millions of years to form these fossil fuels and everyday we use way more than we can find we may have a surplus for now but we may run out sooner than some think 
 
        
             
        
        
        
Answer:
D:   The side of Magnet A that's attracted to Magnet B's south pole must be Magnet A's north pole
Explanation:
D:  The side of Magnet A that's attracted to Magnet B's south pole must be Magnet A's north pole because
1) opposite poles attract each other
2) similar poles repel each other
3)magnetic lines of force start at the north pole and end at the south pole
 
        
                    
             
        
        
        
Answer
given,
ω₁ = 0 rev/s
ω₂ = 6 rev/s
t = 11 s
Using equation of rotational motion
The angular acceleration is
   ωf - ωi = α t
   11 α = 6 - 0
       = 0.545 rev/s²
The angular displacement
   θ₁= ωi t + (1/2) α t²
   θ₁= 0 + (1/2) (0.545)(11)^2
   θ₁= 33 rev
case 2
ω₁ = 6 rev/s
ω₂ = 0 rev/s
t = 14 s
Using equation of rotational motion
The angular acceleration is
   ωf - ωi = α t
   14 α = 0 - 6
         = - 0.428 rev/s²
The angular displacement
   θ₂= ωi t + (1/2) α t²
   θ₂= 6 x 14 + (1/2) (-0.428)(14)^2
   θ₂= 42 rev
total revolution in 25 s is equal to 
θ =  θ₁ +  θ₂
θ =  33 + 42
θ = 75 rev 
 
        
             
        
        
        
The mass of the ion is 5.96 X 10⁻²⁵ kg
<u>Explanation:</u>
The electrical energy given to the ion Vq will be changed into kinetic energy 
As the ion moves with velocity v in a magnetic field B then the magnetic Lorentz force Bqv will be balanced by centrifugal force  .
.
So,

and 

Right from these eliminating v, we can derive 

On substituting the value, we get:

m = 5.96 X 10⁻²⁵ kg.