# Show that Newton's 2nd Law is Not valid in accelerating reference frame

1. Jun 21, 2015

### Tonia

1. The problem statement, all variables and given/known data
Show that Newton's Second Law is NOT valid in a reference frame moving past the laboratory frame of problem 1 with a constant acceleration?
Problem 1: In a laboratory frame of reference, an observer notes that Newton's Second Law is valid. Show that it is also valid for an observer moving at a constant speed, small compared with the speed of light, relative to the laboratory frame.
dx^1/dt = dx/dt-v
d^2x^1/dt^2= d^2x/dt^2
force new = force old
acceleration = d^2x/dt^2 and if v is constant = dv/dt = 0

2. Relevant equations
F = ma

3. The attempt at a solution
I am not sure how to solve it

Last edited by a moderator: Jun 21, 2015
2. Jun 21, 2015

### FactChecker

If F1 = m1a1 measured in the Lab reference frame 1, which of F, m, and a, would be the same and which would be different if they are measured in an accelerating frame 2? If F1 = F2 and m1 = m2, but a1 ≠ a2, then you can say the F2 ≠ m2a2

3. Jun 21, 2015

### Tonia

Would the F and m be the same in the accelerating frame? If so, why?

4. Jun 21, 2015

### Tonia

Let me try this again: F would change, and m would stay the same?