Two identical particles each of mass M and charge Q are placed a certain distance apart. If they are in equilibrium under mutual gravitational and electric force then calculate the order of Q/M in SI units.

 Q / m = 8.61 10⁻¹¹ C / kg

Explanation:

For this exercise we use the gravitational force of attraction

the electric force

indicate that the two forces are equal

     G m₁ m₂ / r² = k q₁ q₂ / r²

they also say that the two masses are equal and the two charges are equal

     G m² = k Q²

     Q / m =  

we calculate

      Q / m =

      Q / m =

       Q / m = 0.861 10⁻¹⁰

       Q / m = 8.61 10⁻¹¹ C / kg

insects!

explanation: