Answer:
The ball will be attracted to the negatively charged plate. It'll touch and pick up some electrons from the plate so that the ball becomes negatively charged. Immediately the ball is repelled by the negative plate and is attracted to the positive plate. The ball gives up electrons to the positive plate so that it is positively charged and suddenly attracts to the negative plate again, flies over to it and picks up enough electrons to be repulsed by negative plate and again to the positive plate and that continues. 
 
        
             
        
        
        
Answer: 0.85 meters (with and without sigfigs)
Explanation: To find the wavelength, you just have to switch around the equation for wave speed: v (wave speed) = λ (wavelength)*f (frequency) so λ (wavelength) = v (wave speed)/f (frequency). You don't have the wave speed but you can calculate it. Since wave speed is measured in meters/second or m/s, you just have to divide the amount of meters you were given by the amount of seconds. You will get 340 m/s. Next, you have to plug the values into the equation: λ (wavelength) = 340 m/s (wave speed)/400 Hz (frequency). The answer is 0.85 meters (seconds cancel) and has the correct number of significant figures.
 
        
             
        
        
        
Answer:
E=1100V/m
                                                                      
Explanation:
Given           required           <u>solution</u>
V=6.6v         E=?                   V=Ed ;    V is the potential difference between                                                              
d=D/2=1.2cm/2=0.6cm=0.006m             the   halfway                   
                                                                E is the electric field between the two                                                                               
                                                                        plates.
                                                               d is the distance between the halfway.
 So we can use the above formula to calculate the electric field.
     V=Ed   from this E=V/d  substitute the values from the given equation.
E=6.6v/0.006m
E= 1100 v/m 
                                                                      
 
        
             
        
        
        
Answer:
33.61°
Explanation:
Refractive index is equal to velocity of the light 'c' in empty space divided by the velocity 'v' in the substance.
Or ,
n = c/v.
v is the velocity in the medium  (2.3 × 10⁸ m/s)
c is the speed of light in air = 3.0 × 10⁸ m/s
So,  
n = 3.0 × 10⁸ /  2.3 × 10⁸
n = 1.31
Using Snell's law as:
 
Where,  
 is the angle of incidence  ( 25.0° )
  is the angle of incidence  ( 25.0° )
 is the angle of refraction  ( ? )
 is the angle of refraction  ( ? )
 is the refractive index of the refraction medium  (air, n=1)
 is the refractive index of the refraction medium  (air, n=1)
 is the refractive index of the incidence medium (glass, n=1.31)
 is the refractive index of the incidence medium (glass, n=1.31)
Hence,  
 
Angle of refraction =  = 33.61°
 = 33.61°