A) 
The energy of an x-ray photon used for single dental x-rays is

The energy of a photon is related to its wavelength by the equation

where
is the Planck constant
is the speed of light
is the wavelength
Re-arranging the equation for the wavelength, we find

B) 
The energy of an x-ray photon used in microtomography is 2.5 times greater than the energy of the photon used in part A), so its energy is

And so, by using the same formula we used in part A), we can calculate the corresponding wavelength:

Answer:
The correct option is;
A. honk your horn if you cannot see at least 200 ft ahead
Explanation:
According the California Driver Handbook on Safe Driving Practices, it is required of the driver driving on a narrow mountain road without clear visualization of what is 200 ft ahead of her or him to honk the horn of the vehicle.
The sounding of the horn will alert those ahead of the driver of the possible danger due to her or his oncoming vehicle so that they (those ahead of the driver's oncoming vehicle) can react appropriately.
Answer: 72m/1 min and 24 secs
Explanation:
He swims .75m/sec. im pretty sure i got it but let me know and ill help you out if its wrong
<span>In 1964, while experimenting with the Holmdel Horn Antenna, which was used as a radio telescope, Penzias and Wilson accidentally discovered the microwave background radiation that exists universally. The Holmdel Horn Antenna was used to support the "Big Bang Theory" as opposed to the "Steady State Theory".</span>
Answer:
F = 789 Newton
Explanation:
Given that,
Speed of the car, v = 10 m/s
Radius of circular path, r = 30 m
Mass of the passenger, m = 60 kg
To find :
The normal force exerted by the seat of the car when the it is at the bottom of the depression.
Solution,
Normal force acting on the car at the bottom of the depression is the sum of centripetal force and its weight.



N = 788.6 Newton
N = 789 Newton
So, the normal force exerted by the seat of the car is 789 Newton.