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:
blue star is hotter than red
Explanation:
The colour of a star depends on its temperature.
Lesser the temperature means lesser be the energetic. less energy means longer wavelength. Between blue and red, red colour has longer wavelength. So, the red colored star is colder than blue coloured star.
Blue coloured star is hotter than red coloured star.
Answer: a) The rate constant, k, for this reaction is 
b) No 
does not depend on concentration.
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
Given: Order with respect to 
= 1
Thus rate law is:
a) ![Rate=k[A]^1](https://tex.z-dn.net/?f=Rate%3Dk%5BA%5D%5E1)
k= rate constant
![0.00250=k[0.484]^1](https://tex.z-dn.net/?f=0.00250%3Dk%5B0.484%5D%5E1)
The rate constant, k, for this reaction is
b) Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Thus does not depend on concentration.
Friction-reducing technologies used in the Variable Compression Turbo Engine are Diamond-like coating on valve lifters, micro finishing on crankshaft and camshaft and mirror bore coating on cylinder wall.
<u>Explanation:</u>
Variable compression is a technology to adjust the compression of an internal combustion engine while the engine is in operation. At this time friction may occur that need to be reduced. To reduce this friction some technologies are used like
- Diamond-like coating on valve lifters
- Micro finishing on crankshaft and camshaft
- Mirror bore coating on cylinder wall
A hydrogen free diamond like carbon coating is applied to an engine valve lifter to reduce mechanical loss. Micro finishing on crankshaft and camshaft achieves improvement in geometric parameters such as roundness. Mirror bore coating on cylinder wall raises energy efficiency by reducing the friction inside the engine.
The final speed when the mass is 40,000kg height is 2.5km and 500,000N of force is 176.8 m / s
According to Newton's second law of motion,
F = m a
F = Force
m = Mass
a = Acceleration
m = 40000 kg
F = 500000 N
a = F / m
a = 500000 / 40000
a = 12.5 m / s²
a = v / t
v = d / t
v = Velocity
t = Time
d = Distance
d = 2.5 km = 2500 m
a = d / t²
12.5 = 2500 / t²
t² = 200
t = 14.14 s
v = 2500 / 14.14
v = 176.8 m / s
Therefore, the final speed is 176.8 m / s
To know more about Newton's second law of motion
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