Complete Question 
A football coach walks 18 meters westward, then 12 meters
eastward, then 28 meters westward, and finally 14 meters
eastward.
a 
 From this motion what is the distance covered 
b
 What is the magnitude and direction of the displacement 
Answer:
a
   
b
 Magnitude 
               
 
  Direction  
 West 
Explanation:
From the question we are told that 
 The first distance covered westward is ![d_w_1  =  18 \  m /tex]     The  first distance covered eastward is [tex]d_e1 =  12 \  m /tex]      The second distance covered westward is [tex]d_w_2  =  28 \  m /tex]      The  second distance covered eastward is [tex]d_e2 =  14 \  m /tex]   Generally the distance covered is mathematically represented as       [tex]D =  d_w1 + d_w2 + d_e1 + d_e2](https://tex.z-dn.net/?f=d_w_1%20%20%3D%20%2018%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%20%20The%20%20first%20distance%20covered%20eastward%20is%20%5Btex%5Dd_e1%20%3D%20%2012%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%20%20%20The%20second%20distance%20covered%20westward%20is%20%5Btex%5Dd_w_2%20%20%3D%20%2028%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%20%20%20The%20%20second%20distance%20covered%20eastward%20is%20%5Btex%5Dd_e2%20%3D%20%2014%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%3C%2Fp%3E%3Cp%3EGenerally%20the%20distance%20covered%20is%20mathematically%20represented%20as%20%3C%2Fp%3E%3Cp%3E%20%20%20%20%20%20%5Btex%5DD%20%3D%20%20d_w1%20%2B%20d_w2%20%2B%20d_e1%20%2B%20d_e2)
=> 
=> 
For the second question eastward is in the direction of the positive x-axis so it would be positive and westward is in the direction of the negative x-axis so it would be negative
 The magnitude of the displacement is 
 
=>   
 
=>  
 
The direction is west 
 
        
             
        
        
        
Answer: Machanical advantage of the machine is 1.86
Explanation: Machanical advantage of a machine is the ratio of the Force to overcome which is the load in this case 24kg * 10= 240N to the force exerted(Effort) to overcome the load in this case 129N.
So, we have
MA = load/effort
 = 240N/129N
 = 1.86.
 
        
             
        
        
        
The time for the echo to return is directly proportional to the distance. vw = fλ. In a given medium under fixed conditions, vw is constant, so that there is a relationship between f and λ; the higher the frequency, the smaller the wavelength.
        
             
        
        
        
So he has 7 sheepleft if i did it correctly
15-8=7
        
                    
             
        
        
        
This is another one of those muddy misleading questions, followed by 
a muddy group of choices from which an answer must be selected.
a).  is absurd.  There's no such thing as a "balanced force", only 
a balanced group of forces.
b).  is probably the choice the question is aiming for.
c).  is not so.  The engines of an airplane do plenty of work lifting the plane 
off the ground, although the force of the engines is never directed upward.
d).  is really awkward.  The object's motion is almost never the cause of the force.
The force is almost always the cause of the object's motion. 
Now for the big 800-lb gorilla in the room:  No moving object needs to be involved 
in order for energy to be flowing or work to be getting done.
-- A radio wave radiates through space.  Straighten out a wire coat-hanger and 
stick it up in the air where the radio wave can pass by it.  Electrical current flows 
through the wire, and you can drain the electrical energy out the bottom of it.   
-- A light bulb is shining.  Some distance away, something it's shining on 
gets warm, because of the heat energy that has shot across to it from the 
light bulb and soaked into it.
-- A lightning bolt jumps from the ground to a passing cloud.  Or, if you feel 
more comfortable with it, a lightning bolt jumps from a cloud to the ground.
It doesn't matter.  Either way, there's enough energy splashing around to 
ignite houses, zap TVs and computers, melt concrete, vaporize water, and 
light up a city.  Although nothing is moving.