The Velocity of a Particle (M = 10 Mg, Q

Multiple Choice

The velocity of a particle (m = 10 mg, q = −4.0 μC) at t = 0 is 20 m/s in the positive x direction. If the particle moves in a uniform electric field of 20 N/C in the positive x direction, what is the particle's speed at t = 5.0 s?

A) 60 m/s
B) 20 m/s
C) 45 m/s
D) 40 m/s
E) 70 m/s