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
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
then the period is:

Therefore runner B has the smaller period
Answer: A is 70 B is 45 and C is 50
Step-by-step explanation:
Answer:
Step-by-step explanation:
$19.50
-$15.50=
$4.00
1slice of pizza and 1soda is $4
so 2slices of pizza and 2 sodas is $8
$15.50-$8=$7.50
Now you have 3 slices of pizza left
$7.50/3slices=$2.50
1slice of pizza is $2.50