If an electron is accelerated from rest through a potential difference of 9.9 kv, what is its resulting speed? (e = 1.60 × 10-19 c, k = 1/4πε0 = 8.99 × 109 n · m2/c2, m el = 9.11 x 10-31 kg) if an electron is accelerated from rest through a potential difference of 9.9 kv, what is its resulting speed? ( = 1.60 × 10-19 c, = 1/4π = 8.99 × 109 n · m2/c2, el = 9.11 x 10-31 kg) 4.9 × 107 m/s 3.9 × 107 m/s 2.9 × 107 m/s 5.9 × 107 m/s