A charge of 284 mu C is held fixed at the origin A second ch

A charge of 2.84 mu C is held fixed at the origin. A second charge of 2.84 mu C is released from rest at the position (1.29 m, 0.578 m). If the mass of the second charge is 2.66 g, what is its speed when it moves infinitely far from the origin? At what distance from the origin does the 2.84 mu C charge attain half the speed it will have at infinity?

Solution

Distance between the charges r = sqrt ( 1.29² + 0.578² ) = 1.41 m

k q q\' / r = 1/2 mv²

v = sqrt (2 k q q\' / r m )

= sqrt [ ( 2 * 9 * 10⁹ * 2.84 * 10^-6 * 2.84 * 10^-6 ) / ( 1.41 * 0.00266 ) ]

= 6.22 m/s