Acceleration = ?

Most recent answer: 05/16/2013

What affects acceleration?
- Tani (age 14)
Waterbury, CT
According to Newton, acceleration equals force divided by mass.  The force can come from many different sources:  gravity, electric and magnetic field forces on charged particles, friction, tensions in strings,  etc.   The usual way of expressing it in standard textbooks is F = MA.
Another, separate, question is 'What is mass?'.  In a rather circular argument, mass is defined as that quantity that resists acceleration due to force.   On earth, mass can be related to the amount of force on a weight scale.  In outer space however, scales don't work So you have to go back to the original definition  M = F/A. 


(published on 05/16/2013)