Answer:
a) the three longest wavelengths = 4.8m, 2.4m, 1.6m
b) what is the frequency of the third-longest wavelength = 75Hz
Explanation:
The steps and appropriate formula and substitution is as shown in the attached file.
 
        
             
        
        
        
Answer:
The force due to air resistance is 256 N.
Explanation:
Given;
mass of the plane, m = 5 kg
applied force on the plane, Fa = 706 N
the net force on the plane, ∑F= 450 N
Let the force due to air resistance = Fr
The net force on the plane is given as;
Net force = applied force - force due to air resistance
∑F = Fa - Fr
Fr = Fa - ∑F 
Fr = 706 - 450
Fr = 256 N.
Therefore, the force due to air resistance is 256 N.
 
        
             
        
        
        
Answer:

Explanation:
We can use the conservation of momentum. The initial momentum is equal to the final momentum:
x-coordinate

 
  
 (1)
 (1) 
y-coordinate 

 
  
 (2)
 (2)
We can divide equations (2) and (1):



 
 
 
 
I hope it helps you!
            
 
        
                    
             
        
        
        
Answer:
Coefficient of friction = 0.5
Explanation:
Given:
Mass of box = 5 kg
Force applied = 20 N
Acceleration = 2 m/s²
Find:
Coefficient of friction
Computation:
Friction force = Mass x Acceleration.
Friction force =  5 x 2 
Friction force = 10 N
Coefficient of friction = Friction force / Force applied
Coefficient of friction = 10 / 20
Coefficient of friction = 0.5