3. Through what potential difference would you need to accelerate an alpha particle, starting from rest, so that it will just reach the surface of a 15 fm diameter uranium 238 nucleus (Z-92).

Respuesta :

Answer:

17664000 V

Explanation:

We are given that

Diameter of uranium,d=15fm

Radius,r=[tex]\frac{d}{2}=\frac{15}{2}=7.5\times 10^{-15}m[/tex]

1 fm=[tex]10^{-15} m[/tex]

Z=92

Charge on uranium particle=[tex]q_1=92\times 1.6\times 10^{-19}[/tex] C

Because charge on proton=[tex]1.6\times 10^{-19} C[/tex]

Charge on alpha particle=[tex]q_2=2e=2\times 1.6\times 10^{-19} C[/tex]

We have to find the potential difference would be needed to accelerate an alpha particle.

Speed of alpha particle=0

Therefore, k.E of alpha particle=0

Energy gained by alpha particle=[tex]E=q_2 V[/tex]

[tex]E=0-U=U=\frac{kq_1q_2}{r}[/tex]

[tex]q_2V=\frac{kq_1q_2}{r}[/tex]

[tex]V=\frac{kq_1}{r}[/tex]

Where [tex]K=9\times 10^9[/tex]

Substitute the values

[tex]V=\frac{9\times 10^9\times 92\times 1.6\times 10^{-19}}{7.5\times 10^{-15}}[/tex]

[tex]V=17664000 V[/tex]

Lanuel

The potential difference that is required to accelerate an alpha particle is [tex]V = 2.35 \times 10^{19}\; Volts[/tex].

Given the following data:

  • Atomic number of uranium = 92
  • Diameter of uranium = 15 fm

Radius = [tex]\frac{Diameter}{2} = \frac{15\;fm}{2} = 7.5 \times 10^{-15}\;m[/tex]

We know that a proton has a charge of [tex]1.6 \times 10^{-19}\;C[/tex]

Coulomb constant, k = [tex]9 \times 10^9[/tex]

First of all, we would determine the charge on both an uranium and alpha particle.

For uranium:

[tex]q_1 = 92 \times 1.6 \times 10^{-19}\\\\q_1 = 1.47 \times 10^{-19}\;C[/tex]

For alpha particle:

[tex]q_2 = 2 \times 1.6 \times 10^{-19}\\\\q_2 = 3.2 \times 10^{-19}\;C[/tex]

Next, we would determine the potential difference that is required to accelerate an alpha particle by using this derived formula:

[tex]E = qV[/tex]

[tex]q_2V = F_q\\\\q_2V = \frac{kq_1q_2}{r^2} \\\\q_2Vr^2=kq_1q_2\\\\V=\frac{kq_1}{r^2}[/tex]

Substituting the given parameters into the formula, we have;

[tex]V = \frac{9 \times 10^9 \times 1.47 \times 10^{-19}}{(7.5 \times 10^{-15})^2} \\\\V = \frac{1.323 \times 10^{-9}}{5.625 \times 10^{-29}}\\\\V = 2.35 \times 10^{19}\; Volts[/tex]