Explanation:
The relationship of the speed of sound, its frequency, and wavelength is the same as for all waves: vw = fλ, where vw is the speed of sound, f is its frequency, and λ is its wavelength.
 
        
             
        
        
        
I'll assume that the chair has four legs. 
Since the chair weights 3.7 kg by itself, it will weigh (79+3.7)=82.7 kg with the person sitting on it. And each of the chair's legs will take about (82.7/4)=20.675 kg. 
Each leg touches the floor in a circle with 1.3cm diameter. The area of that circle is about (3.14*(1.3/2)^2)=1.327 cm^2. 
Pressure is measured by force per area. So, the pressure from each leg is about 20.675kg / 1.327cm^2. That simplifies to 15.58 kg/cm^2.
        
             
        
        
        
No, options are given but I believe the answer would be
In a water cycle Solid state of matter has the particles closest together.
        
                    
             
        
        
        
Answer:
(a)  The horizontal ground reaction force  
(b)  The vertical ground reaction force 
(c)   The resultant ground reaction force 
Explanation:   
Given
John mass , m = 65 kg
Horizontal acceleration , 
Vertical acceleration , 
(a) Using Newton's 2nd law in horizontal direction 

=>
Thus the horizontal ground reaction force  
(b) Using Newton's 2nd law in vertical direction

=>
=>
Thus the vertical ground reaction force 
(c)  Resultant ground reaction force is

=>
=>
Thus  the resultant ground reaction force 