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
Mid point of x:
{2-(-6)} : 2
8 : 2
4
mid point of y:
(5-3) : 2
2 : 2
1
so (4,1)
Answer:
The angle for G is 121°.
Step-by-step explanation:
Given that total angles in a triangle is 180° so in order to find the angle of G, first, you hav eto find the value of x :
x + (x - 5) + (3x + 25) = 180°
5x + 20° = 180°
5x = 160°
x = 32°
Next, you have to find the angle of G :
G = 3x + 25
G = 3(32) + 25
G = 96° + 25°
G = 121°