Noble gasses ( insert gases)
To solve this exercise it is necessary to apply the concepts related to Centripetal and Perimeter acceleration of a circle.
The perimeter of a circle is defined by

Where,
r= radius
While centripetal acceleration is defined by

Where,
v= velocity
r= radius
PART A)
The distance of a body can be defined based on the speed and the time traveled, that is
x = v*t
For our values the distance is equal to
x = 15*115=1725m
The plane when going to make the turn from east to south makes a quarter of the circumference that is

The same route you take is the distance traveled, that is




PART B)
With the radius is possible calculate he centripetal acceleration,



Therefore the radius of the curva that the plane follows in making the turn is 1098.17m with a centripetal acceleration of 
I think it's the letter Did (this has to be 20 characters long) it would be Different or would be D
Answer:
LAW 1 : For a given metal and frequency, the number of photoelectrons emitted is directly proportional to the intensity of the incident radiation.
---------------------------------------------
LAW 2: For a given metal, there exists a certain frequency below which the photoelectric emission does not take place. This frequency is called threshold frequency.
-----------------------------------------------
LAW 3: For a frequency greater than the threshold frequency, the kinetic energy of photoelectrons is dependent upon frequency or wavelength but not on the intensity of light.
-----------------------------------------------
LAW 4: Photoelectric emission is an instantaneous process. The time lag between incidence of radiations and emission of electron is 10^-9 seconds.
Explanation: