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:
The correct answer is that they would all hit the ground at the same time. If no air resistance is present, the rate of descent depends only on how far the object has fallen, no matter how heavy the object is. This means that two objects will reach the ground at the same time if they are dropped simultaneously from the same height. This statement follows from the law of conservation of energy and has been demonstrated experimentally by dropping a feather and a lead ball in an airless tube.
Answer:
After refraction at two parallel faces of a glass slab, a ray of light emerges in a direction parallel to the direction of incidence of white light on the slab. As rays of all colours emerge in the same direction (of incidence of white light), hence there is no dispersion, but only lateral displacement.
Answer:
Explanation:
It means that you only need apply 1/4th of the actual force required to operate the lever as you have an mechanical advantage which permits you to do 4 times the work with the same amount of effort.
Answer:
atmosphere
Explanation:
majority of nitrogen found in atmosphere,it's about 78% and present in form of gas
