Answer: 6.36
Explanation:
Given
Radius of grindstone, r = 4 m
Initial angular speed of grindstone, w(i) = 8 rad/s
Final angular speed of the grindstone, w(f) = 12 rad/s
Time used, t = 4 s
Angular acceleration of the grinder, 
α = Δw / t
α = w(f) - w(i) / t
α = (12 - 8) / 4
α = 4/4 = 1 rad/s²
Number of complete revolution in 4s = 
Δθ = w(i).t + 1/2.α.t²
Δθ = 8 * 4 + 1/2 * 1 * 4²
Δθ = 32 + 1/2 * 16
Δθ = 32 + 8
Δθ = 40 rad/s
40 rad/s = 40/2π rpm = 6.36 rpm
Therefore, the grindstone does 6.36 revolutions during the 4 s interval
 
        
             
        
        
        
The answer is Solvent. The reason is in the wording, 'the substance that does the dissolving.' A solvent does the dissolving, a solute is something that can be dissolved. 
 
        
             
        
        
        
Answer:As sunlight passes through the atmosphere, all UVC and most UVB is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA is not filtered as significantly by the atmosphere. Is there a connection between ozone depletion and UV radiation? Ozone is a particularly effective absorber of UV radiation.
Explanation:
I had old notes
 
        
                    
             
        
        
        
Answer:
   W / A = 39200 kg / m²
Explanation:
For this problem let's use the equilibrium equation of / newton
            F = W
Where F is the force of the door and W the weight of water
          W = mg
We use the concept of density
         ρ = m / V
         m = ρ V
The volume of the water column is
           V = A h
We replace
          W = ρ A h g
On the other side the cylinder cover has a pressure
           P = F / A
           F = P A
 We match the two equations
        P A = ρ A h g
         P = ρ g h
         P = 39200 Pa
The weight of the water column is
        W  = 1000 9.8 4 A
        W / A = 39200 kg / m²
 
        
             
        
        
        
Answer:
5. All of the statements are true; non is false
Explanation: