Finding Broglie wavelength after acceleration

AI Thread Summary
The discussion centers on calculating the new kinetic energy (KE) after acceleration, starting with a KE of 100 eV. The new velocity is derived using the formula v(new) = √(2KE/m), resulting in a speed of approximately 5.9 x 10^6 m/s. Participants clarify that the new KE remains 100 eV multiplied by the charge of an electron, and there is confusion about whether to add this new velocity to an initial velocity of 0.2 nm. The kinematic equation v(t) = v0 + at is referenced to explain how to find the final velocity after acceleration. The conversation emphasizes the importance of understanding how to combine initial and accelerated velocities.
Physicsq
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Homework Statement
A free electron initially moves along the positive x-axis direction with the de Broglie wavelength of 0.20 nm. If this election is further accelerated by 100 eV along the positive x-axis direction, what is the de Broglie wavelength of the electron after the acceleration?
Relevant Equations
λ=h/p
KE = 1/2mv^2
KE = 100eV x (1.6x10^-19)

v(new) = √(2KE/9.1×10^-31 )
= 5.9x10^6m/sv(original) = h/λm
= 6.6x10^-34 / (0.2x10^-9 x 9.1x10^-31)
= 3.64x10^6m/s
 
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Physicsq said:
1

That’s it?

Do you not know how to find the new KE after it has been accelerated?

Zz.
 
New KE will be 100eV x (1.6x10^-19)?

Do I add the velocity from the new KE to the current velocity traveling at 0.2nm?
 
Physicsq said:
New KE will be 100eV x (1.6x10^-19)?

Do I add the velocity from the new KE to the current velocity traveling at 0.2nm?

From lessons on kinematics, you had this:

v(t) = v0 + at

where v(t) is the velocity at time t, a is the acceleration, and v0 is the initial velocity. What that equation say is that if you accelerate a particle over time t, then its final velocity will be the initial velocity added to whatever velocity it has gained from acceleration.

Does that answer your question?

Zz.
 
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