-- What's the volume of a cylinder with radius=1m and height=55m ?
         ( Volume of a cylinder = π R² h )
-- How much does that volume of water weigh ?
            1 liter of water = 1 kilogram of mass
            Weight = (mass) x (acceleration of gravity)  
-- What's the area of the bottom of that 1m-radius cylinder ?
       Pressure  =  (force) / (area)
        
             
        
        
        
Answer:
Explanation:
Given
Weight of Person 
Cave is  deep
 deep
Breaking stress 
Net Force on Person 




The shortest time such that the person can be taken out of cave

where 
h=distance moved
t=time
a=acceleration



 
                     
 
        
             
        
        
        
Answer:
True
Explanation:
Matter can be in the form of a particle or a wave. This is known as the dual nature of matter. This concept was proposed by Louis de Broglie and was named after him. This phenomenon has been observed for all the elementary particles.
The de Broglie wavelength is given by

Where 
h = Planck's constant
p = Particles momentum
m = Mass of particle
v = Velocity of particle
 
        
             
        
        
        
Explanation:
You need two, maybe three things - something that's vibrating, a medium for those vibrations to propagate in, and a listener to hear it or recording equipment to pick it up