Calculating Initial Acceleration: 63g Particle, 59μC Charge

[Punchlinegirl]

A particle of mass 63 g and charge 59 \mu C is released from rest when it is 71 cm from a second particle of charge -27 \mu C. Determine the magnitude of the initial acceleration of the 63 g particle. Answer in units of m/s^2.

I used Coulomb's Law, F= 1/4\pi \epsilon_o * (5.9 x10^-6 * -2.7 x 10^-6) / .71^2
I know that E_o = 8.85 x 10^-12.
Solving this gave me .284.
Then I set it equal to ma.
63 a = .284
Solving for a gave me .00451 m/s^2.
Can someone tell me what I'm doing wrong?

 

[Astronuc]

Make sure the units are correct. If the force is in N, which it appears to be, then the mass must be in kg (0.063 kg = 63 g).

Perhaps it would be helpful to keep a chart of cgs and mks units available.

 

[Punchlinegirl]

so if the rest of my setup is right, I get .063a= .284.
Solving for a gives me 4.51 m/s^2, which still isn't right.
Am I doing something else wrong?

 

[lightgrav]

59 microCoulombs = 59.E-6 C , not 5.9E-6 C
same for the 27 uC .