A. Ask other people for their opinion. :)
        
             
        
        
        
After 5 seconds the stone will have fallen 49 m
        
                    
             
        
        
        
Answer:
um how about no.. this is not the site for what you're looking for...
Explanation:
 
        
                    
             
        
        
        
Answer:
a ) 1.267 radian
b ) 1.084 10⁻³ mm
Explanation:
Distance of screen D = 1.65 m 
Width of slit d = ?
Wave length of light   λ  = 687 nm.
Distance of second minimum fro centre y = 2.09 cm
Angle of diffraction = y / D 
=  2.09 /1.65  
= 1.267. radian 
Angle of diffraction of second minimum
= 2 λ / d 
so 2 λ / d = 1.267
d = 2 λ / 1.267 = (2 x 687 ) /1.267 nm
=1084.45 nm = 1.084 x 10⁻³ mm. 
 
        
             
        
        
        
The magnetic particles are mixed with other substances to make it flexible.