Answer:1) the total distance is the sum of the two distances
60 km + 45 km = 105 km
2) The displacement is the net movement, or the difference between the initial position and the final position
Call x the initial position, then the final position is x + [60km - 45km]
And the displacement is x + (60km - 45km) - x =60km -45 km = 15 km
Explanation:
Answer:
The first harmonic is: 250Hz, second harmonic 500Hz, third harmonic 750Hz.
Explanation:
Use the frequency f, speed v, and wavelentgh L relationship:

We are given the speed v=400 m/s. The base wavelength on a string of length 80cm is twice the length of the string (a "half wave" along the full length of the string), so:

The fundamental frequency (first harmonic) is 250 Hz
The second harmonic is produced by one full wave across the string (adding one node in the middle), so L=80cm in this case, therefore the second harmonic frequency is: f2 = 2*250=500Hz
the third harmonic add another node (and a half wave) to the pattern and the wavelength will be 2/3 of 80cm, so f3=3*250Hz = 750Hz