points a, b, and c have the following electric potentials:
V_a = -50volts, V_b = +2volts, V_c = -70volts
compute the work required by an external agen to transport the following charges at constant speed between the endpoints indicated:
a) +2coulomb from a to c
b) -2coulomb from c to a
c) -2coulomb from b to c
acceleration a = (q/m)E = v^2/r where q is charge, m is mass, E is electric field , v is velocity in m/s ---> since the question asks for constant speed, acceleration = 0
electric potential difference V = kq[(1/r_a) - (1/r_b)] where q is charge, k is constant
9*10^9, r is radius/distance in meters
electric potential V = kq/r
work W = F*d, where F is force in newtons, d is displacement in meters
F = kq_1q_2/r^2 where k is constant, q is charge, r is radius/distance in meters
The Attempt at a Solution
my main issue is determining what equation to use, i am not sure about how to derive the correct equation.
it seems that i could use the electric potential difference equation because it involves one charge but i do not know the radii for the two potentials, can i determine the radii without a charge for each one?
i also need to calculate force, but the equations involved either involve wo charges, where i only am given one, or a radius, again which i am not given.
even still how do i calculate work, W = F*d
any tips on how to get started appreciated...