- #1
NeroBlade
- 11
- 0
Hi I've been revising and came across some questions which I do not understand how they obtained the answer could you guys help?
1.
Show that the momentum, p, of a particle of mass m is related to its kinetic energy, KE by the relationship p^2 = 2m KE
Use the above relationship to calculate the accelerating potential required for
electrons to have a de Broglie wavelength of 4·5 × 10^(–11) m.
And the answer turns out to be 645V.
2.
A magnet moves towards a coil as shown (solenoid circuit). Use Lenz’s law to explain in which direction the current will flow through the turns of the coil. The coil is now situated in a uniform magnetic field changing at a rate of 0·43Ts^–1.
r = 0.046m
B = 0.43Ts^-1
N = 1300
Total Resistance = 6.6 ohms
A = 2 *(pi)* r^2 = 0.0133m^2
Calculate the current flowing in the ammeter.
Formulas I've thought of is R = V/I, E = NBA / t and I set V = 1
However the formula turned out to be
I = (1300 * 0.43 * (pi) * ((0.046)^2)) / 6.8 = 0.55A
Problem I got is how did R become the demominator (6.8)?
3.
In the LINAC, the protons are accelerated from rest through 3 gaps each with an accelerating p.d. of 36kV.
KE in J is 1.7*10^(-14)J
Speed of protons 4.5 * 10^6 ms^-1
The radius of the synchrotron is 12·5 m. Calculate the value of the magnetic flux
density in the synchrotron when the speed of the protons is 9·4 × 10^6 ms^–1.
Equation I could think of is
F = (mv^2) / r where do I go from here?
Any help would be gr8
Cheers
1.
Show that the momentum, p, of a particle of mass m is related to its kinetic energy, KE by the relationship p^2 = 2m KE
Use the above relationship to calculate the accelerating potential required for
electrons to have a de Broglie wavelength of 4·5 × 10^(–11) m.
And the answer turns out to be 645V.
2.
A magnet moves towards a coil as shown (solenoid circuit). Use Lenz’s law to explain in which direction the current will flow through the turns of the coil. The coil is now situated in a uniform magnetic field changing at a rate of 0·43Ts^–1.
r = 0.046m
B = 0.43Ts^-1
N = 1300
Total Resistance = 6.6 ohms
A = 2 *(pi)* r^2 = 0.0133m^2
Calculate the current flowing in the ammeter.
Formulas I've thought of is R = V/I, E = NBA / t and I set V = 1
However the formula turned out to be
I = (1300 * 0.43 * (pi) * ((0.046)^2)) / 6.8 = 0.55A
Problem I got is how did R become the demominator (6.8)?
3.
In the LINAC, the protons are accelerated from rest through 3 gaps each with an accelerating p.d. of 36kV.
KE in J is 1.7*10^(-14)J
Speed of protons 4.5 * 10^6 ms^-1
The radius of the synchrotron is 12·5 m. Calculate the value of the magnetic flux
density in the synchrotron when the speed of the protons is 9·4 × 10^6 ms^–1.
Equation I could think of is
F = (mv^2) / r where do I go from here?
Any help would be gr8
Cheers