AYUDA CON ESTO!!! ALGUIEN PORFAVOR

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):
[tex]Period = \frac{1}{frequency} = \frac{1}{160} \,minutes= 0.00625\,\,minutes = 0.375\,\,seconds[/tex]
second problem:
Runner A does 200 loops in 60 minutes so his frequency is:
[tex]\frac{200}{60} = \frac{10}{3} \approx 3.33[/tex] 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:
[tex]\frac{200}{65} = \frac{40}{13} \approx 3.08[/tex] loops per minute
then the period is:
[tex]\frac{13}{40} =0.325\,\,\,minutes[/tex]
Therefore runner B has the smaller period