Haven't taken physics but I would assume if her friend is standing in front of her that you would add up the speeds and get 30 km/hr.
27.5 because of you divide the 55miles with the time you get your velocity which is the speed.
Answer:
The minimum thickness = 83.92 nm
Explanation:
The relation between the wavelength in a particular medium and refractive index 
where ;
= wavelength of the light in vacuum
n = refractive index of medium with respect to vacuum
For one phase change :

Replacing 1.43 for n and 480 nm for λ; we have:

t = 83.92 nm
Thus; the minimum thickness = 83.92 nm
Answer:
12+ 18 divide by 2 is the average minutes
The exact distance from the seismic station to the epicenter is 6000 km.
<h3>
Epicenter of earthquake</h3>
The earthquake's epicenter is the point above the fault location on the earth's surface.
Given that:
A p-wave arrives at 3:00:00 and the s-wave arrives at 3:07:20.
Difference in arrival time = 3:07:20 - 3:00:00 = 7 minutes 20 seconds
From the earthquake time travel graph, a time difference of 7 min 20 sec is at x = 6
The exact distance from the seismic station to the epicenter is 6000 km.
Find out more on Epicenter of earthquake at: brainly.com/question/1969968