What statement is true because of Newton's Second Law?
2 answers:
You might be interested in
Kinetic energy: the energy of motion
Work: the change in kinetic energy
Power: the rate of work done
Explanation:
The kinetic energy of an object is the energy possessed by the object due to its motion. Mathematically, it is given by:
where
m is the mass of the object
v is its speed
The work done an object is the amount of energy transferred; according to the energy-work theorem, it is equal to the change in kinetic energy of an object:
where
is the final kinetic energy
is the initial kinetic energy
Finally, the power is the rate of work done per unit time. Mathematically, ti can be expressed as
where
W is the work done
t is the time elapsed
Learn more about kinetic energy, work and power:
#LearnwithBrainly
Answer:
The wavelength is 173 nm.
Explanation:
This kind of phenomenon is known as photoelectric effect, it occurs when photons of light inside the metal surface and if they have the right amount of energy electrons absorb it and got expelled from the metal as photo electrons. The maximum kinetic energy of that photo electrons is given by the expression:
(1)
With E the energy of the photon and Φ the work function of the material. The work function is a value characteristic of each material and is related with how much the electron is attached to the material, the energy of the photon is the Planck's constant (h=) times the frequency of light (
) , then (1) is:
(2)
The frequency of an electromagnetic wave is related with the wavelength () by:
(3)
with c the velocity of light (c=)
Using (3) on (2):
Solving for :
That's the work function of the metal we're dealing. So now if we want to know the wavelength to obtain the double of the kinetic energy we use:
Solving for :