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 = -4.
Step-by-step explanation:
25(√5)^a * (√5) ^3 = 5√5
25*5^a/2 * 5^3/2 = 5*5^1/2
25*5^a/2 = 5*5^1/2 / 5^3/2
25*5^a/2 = 5^1 *5^1/2 / 5^3/2
25*5^a/2 = 5^3/2 / 5^3/2 = 1
5^a/2 = 1/25 = 5^-2
The bases are equal, so
a/2 = -2
a = -4.
The <em>correct answer</em> is:
D) reflect over the y axis and then reflect again over the y axis.
Explanation:
Logically, if we reflect a figure across the y-axis and then reflect across the y-axis again, we have undone what we originally did, and the figure is back in its original position.
Algebraically, reflecting across the y-axis maps every point (x, y) to (-x, y). Reflecting this point across the y-axis maps (-x, y) to (x, y); this is our original point.
Answer:
7 
Step-by-step explanation:
In order to solve an equation like this, you'll need to find a common denominator for your Fraction.
7
+ 
7
+ 
7 
4/5 (20x - 10)...use distributive property...basically multiplying the 4/5 by everything in the parenthesis,
4/5 * 20x - 4/5 * 10 =
16x - 8