An object is accelerating at -6.2 m/s? It comes to a stop after 2.0 seconds. What was its initial velocity? A. -2.7 m/s
B. 2.7 m/s
C. 12.4 m/s
D. -12.4 m/s
NEED ASAP.
WILL GIVE BRAINLIEST.

Two point charges lie on the x axis. a charge of + 2.30 pc is at the origin, and a charge of − 4.50 pc is at x=−11.0cm. what third charge should be placed at x=+26cm so that the total electric field at x=+13.0cm is zero? express your answer to three significant figures and include appropriate units.