Answer:
The minimum coefficient of static friction between the road and the car's tires is 0.816
Option "C"
Explanation:
Given;
velocity of the car, v = 40.0 m/s
radius of horizontal curve, r = 200 m
For a minimum coefficient of static friction between the road and the car's tires that will allow the car to travel at the given speed without sliding, centripetal force must equal frictional force.

where;
μ is the minimum coefficient of static friction

Thus, the minimum coefficient of static friction between the road and the car's tires is 0.816
Option "C"
Answer:
94.82 nm
Explanation:
We have given that wavelength 
We have to find the minimum film thickness that produces the least reflection
minimum thickness is given by 
here n is given n=1.45
so minimum thickness 
so the minimum film thickness will be 94.82 nm
An electron shell can hold 2(n^2) electrons (technically) where n is the shell number, i.e. shell 1 can hold 2, shell 2 can hold 8, 3 holds 18 and so on.
The atomic number of Nitrogen is 7, i.e. it has 7 electrons (to match its 7 protons, assuming it isn't an ion).
With the atomic number, you simply start from shell 1 and work out. So we put 2 electrons in shell 1, leaving us with 5 left. Shell 2 can hold 6 so we can fit all 5 in.
In other words, you should have 2 electron shells on the atom, shell 1 with 2 e- and shell 2 with 5 e-.
Least count of the pulse stopwatch is given by

this means each division of the stopwatch will measure 0.1 s of time
After 3 journeys from one end to other we can see that total time that is measured here is shown by the clock as 52nd division
So here total time is given as
Time = (Number of division) (Least count)
now we will have


Using the "v = f. λ" <span>equation...
Your "v" or </span>velocity = 156.25 meters/second