Answer:
cell wall
Explanation:
A cell wall is a rigid layer that surrounds a plant cell, providing structural support. Other functions of cell walls in plant cells are protection and the transport, absorption, and storage of nutrients and wastes. Cell walls are most commonly found in plants, but they can also be found in other organisms, such as bacteria.
 
        
                    
             
        
        
        
Answer:

Explanation:
Velocity of wave in stretched string is given by the formula

here we know that
T = 4 N
also we know that linear mass density is given as

so we have

now the tension in the string is double
so the velocity is given as


 
        
             
        
        
        
Power = work/time
  
          = 500/10
 
          = 50J/s or 50 watt 
        
             
        
        
        
Answer:
 the   tension in the string an instant before it broke = 34 N
Explanation:
Given that :
mass of the ball m = 300 g = 0.300 kg
length of the string r = 70 cm = 0.7 m
At highest point, law of conservation of energy can be expressed as :


The tension in the string is:

Thus, the   tension in the string an instant before it broke = 34 N
 
        
             
        
        
        
I believe there are two correct answers, and those answers are A and D