PDA

View Full Version : point charges acceleration


pimster987
Sep12-10, 07:24 PM
Q1. If two point charges have equal mass and and charg are released on a frictionless table, each has an initial acceleration (Ao). if instead you keep one fixed and release the other one, what will be its initial acceleration?Ao,2Ao or Ao/2?


Q2. A point charge of mass (m) and charge (q) and another point charge of mass (m) but charge (2q) are released on a frictionless table. If the charge (q) has an initial acceleration (Ao), what will be the acceleration of (2q)?Ao, 2Ao, 4Ao,Ao/2, or Ao/4?

diazona
Sep12-10, 07:58 PM
Show us what you've tried and what you know that might be relevant to the problem.

pimster987
Sep12-10, 09:10 PM
Q1 Since both charges are the same they will repel one another. So I was comparing this problem to a ping pong ball problem I had in Physics I, when the force of the wall equals the force of the ball thrown. Wouldn't the acceleration just be Ao?

Q2 Since F=ma the mass is proportional to the acceleration therefore the acceleration should be 2Ao.

diazona
Sep12-10, 10:13 PM
1. I believe you're correct

2. Look at that equation carefully: the mass is not proportional to the acceleration.

pimster987
Sep13-10, 01:01 PM
They are inversely proportional so the acceleration should be Ao/2?

diazona
Sep13-10, 04:45 PM
You're right that in F=ma, the mass and acceleration are inversely proportional. But what are the masses of the two particles?