What is the current in R₂?

What is the resistance of the combination of resistors?

5. What is the resistance of the combination of resistors?

x₁, x₂, x₃, and x₄ are some numbers.
Answer:

(10³ x₁( x₂+x₃)/(10³ x₁+x₂+x₃) + x₄) Ω

What Voltage is Necessary?

4. To store x₁ mJ of energy in an x₂ μF capacitor, what voltage is necessary?
x₁ and x₂ are some numbers.

Solution:
U = x₁ mJ = x₁ ∙ 10⁻³J
C = x₂ μF = x₂∙ 10⁻⁶ F
V²= 2U/C = 2x₁ ∙ 10⁻³J/(x₂∙ 10⁻⁶ F) = 2∙ 10³x₁/x₂ J/F
V=(2∙10³ x₁/x₂)⁰·⁵ V = 44.7(x₁/x₂)⁰∙⁵ V

Helium Nucleus is Accelerated

3. A helium nucleus is accelerated from rest through a potential difference V to a kinetic energy of X ∙ 10⁻¹³ J. What is the potential difference V? X is some number. Answer: V = E/q = E/(2e) = X ∙ 10⁻¹³ J / (2∙1.60×10⁻¹⁹ C) =  0.312X MV