# Homework Help: Initial Accel of a Particle

1. Jan 31, 2006

### the_d

im stuck on this question if any1 could help i'd appreciate it. A particle of mass 30 g and charge 26 uC is released ffrom rest when it is 59 cm from a second particle of charge -11 uC. The question ask for the initial acceleration of the 30 g particle.

2. Jan 31, 2006

### Smilecdl

Try working out the forces being exerted by the particles.

3. Jan 31, 2006

### Staff: Mentor

What force acts on the particle? (Hint: Consider Coulomb's law)

4. Jan 31, 2006

### the_d

so i work out the forces using coulombs law, but then how do u find acceleration in m/s?

5. Jan 31, 2006

### Staff: Mentor

Use Newton's 2nd law. (Acceleration has units of m/s^2, not m/s.)

6. Jan 31, 2006

### the_d

heres what i got can u tell me if its on the right track

F = k (Q1) (Q2) / r^2

F = (9.0 x 10^9) (26uC) (-11uC) / (0.59m)^2

= -7.39 x 10^13 N

Last edited: Jan 31, 2006
7. Jan 31, 2006

### Staff: Mentor

Realize that $\mu \mbox{C}$ means micro-Coulombs: 1 $\mu \mbox{C} = 10^{-6} \mbox{C}$.

8. Jan 31, 2006

### the_d

when dividing by the mass do i have to change grams to kg?

9. Jan 31, 2006

### Smilecdl

Think of the units that make up a Newton and make sure you use the same

10. Jan 31, 2006

### the_d

thank u guys for ur help