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:
78.5
Step-by-step explanation:
Formula to find area of a circle: A= pi*raduis to the second power
3.14*
First you square the 5
You do this by multiplying 5 times itself
3.14*25
Then you multilpy 3.14 and 25
78.5
Answer:
10.05
Step-by-step explanation:
9.99+9.99+9.99+14.99+14.99
=59.95
70-59.95
=10.05
Answer:
13.70
Step-by-step explanation:
a^2+b^2=c^2
a = side 1
b = side 2
c = hypotenuse
9.2^2 + b^2 = 16.5^2
272.25 - 84.64 = 187.61 =b^2
√187.61 = b = 13.697 = 13.70