Answer:
Problem 1)  frequency:  160 heartbeats per minute, period= 0.00625 minutes (or 0.375 seconds)
Problem 2) Runner B has the smallest period
Problem 3) The sound propagates faster via a solid than via air, then the sound of the train will arrive faster via the rails.
Step-by-step explanation:
The frequency of the football player is 160 heartbeats per minute.
The period is (using the equation you showed above): 

second problem:
Runner A does 200 loops in 60 minutes so his frequency is: 
 loops per minute
   loops per minute
then the period is: 0.3 minutes (does one loop in 0.3 minutes)
the other runner does 200 loops in 65 minutes, so his frequency is:
 loops per minute
   loops per minute
then the period is: 

Therefore runner B has the smaller period
 
        
             
        
        
        
Here, first we need to calculate for Slope:
m = y2-y1 / x2-x1
m = -1-(-4) / -4-(-2)
m = 3 / -2
m = -3/2
Now, y - y1 = m(x - x1)
y + 1 = -3/2(x + 4)
y + 1 = -3/2x - 6
y = -3/2x - 7
In short, Your Equation would be: y = -3/2x - 7
Hope this helps!
        
             
        
        
        
Im pretty sure the answer is 1.675
        
                    
             
        
        
        
Answer: I can give you the volume: 480. But to find the area I need more context to know which are the length and width.