Physics electric charges! Can you help?

Two tiny conducting spheres are identical and carry charges of -17.2C and +53.8C. They are separated by a distance of 2.34 cm. (a) What is the magnitude of the force that each sphere experiences? (b) The spheres are brought into contact and then separated to a distance of 2.34 cm. Determine the magnitude of the force that each sphere now experiences.

1 Answer

  • 8 months ago

    F = (9e9)(17.2)(53.8) / (0.0234)² = 1.52e16 N (same for both)

    (strange problem as that force is huge, enough to lift about 50 mountains)

    in contact, 17.2 of negative charge cancels 17.2 of + charge, leaving total charge of 36.6 C

    IF the two spheres are identical, then they separate, they each get half or 18.3 C

    F = (9e9)(18.3)(18.3) / (0.0234)² = 5.50e15 N (same for both)

    Coulomb's law, force of attraction/repulsion

    F = kQ₁Q₂/r²

       Q₁ and Q₂ are the charges in coulombs

       F is force in newtons

       r is separation in meters

       k = 8.99e9 Nm²/C²

Still have questions? Get your answers by asking now.