thermal energy is the correct answer of number 7
I think it is -3.99 x 102 j
Answer:
The dog catches up with the man 6.1714m later.
Explanation:
The first thing to take into account is the speed formula. It is
, where v is speed, d is distance and t is time. From this formula, we can get the distance formula by finding d, it is 
Now, the distance equation for the man would be:

The distance equation for the dog would be obtained by the same way with just a little detail. The dog takes off running 1.8s after the man did. So, in the equation we must subtract 1.8 from t.

For a better understanding, at t=1.8 the dog must be in d=0. Let's verify:

Now, for finding how far they have each traveled when the dog catches up with the man we must match the equations of each one.






The result obtained previously means that the dog catches up with the man 3.8571s after the man started running.
That value is used in the man's distance equation.


Finally, the dog catches up with the man 6.1714m later.
Answer:
17,947.02 Hz
Explanation:
length (L) = 62 cm = 0.62 m
tension (T) = 70 N
mass per unit length (μ) = 0.10000 g/cm = 0.010000 kg/m
maximum frequency = 18,000 Hz
f = 
f = 
f = n x 67.47
18,000 = n x 67.47
n = 266.8≈ 266
the 267th overtone is the highest overtone that can be heard by this person, and its frequency would be 26 x 67.47 = 17,947.02 Hz