# Understanding meaning of inertial reference frames

## Homework Statement

Which of these situations describes you observing from an inertial reference frame?
a. you are in the car of a train, seated at a table, and the train suddenly slows down
b. you are in the car of a train, going north, and the train goes around a curve to go west
c. you are in the car of a train, and the train is going up a steep hill at a steady speed
d. you are on a ride that spins riders around a horizontal circle

no equations

## The Attempt at a Solution

I read that inertial reference frames are those that are not accelerating. I still do not understand this completely. I think the answer for this question is c, since you would be moving with the train at a constant velocity.

Dr. Courtney
Gold Member
2020 Award

## Homework Statement

Which of these situations describes you observing from an inertial reference frame?
a. you are in the car of a train, seated at a table, and the train suddenly slows down
b. you are in the car of a train, going north, and the train goes around a curve to go west
c. you are in the car of a train, and the train is going up a steep hill at a steady speed
d. you are on a ride that spins riders around a horizontal circle

no equations

## The Attempt at a Solution

I read that inertial reference frames are those that are not accelerating. I still do not understand this completely. I think the answer for this question is c, since you would be moving with the train at a constant velocity.

Of course there is an equation: a = 0 (no acceleration).

Now for each of the four cases, is a = 0, a < 0, or a > 0?

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Noe for each of the four cases, is a = 0, a < 0, or a > 0?

I know this may seem a little goofy, but when I first read your typo “Noe” instead of “Now” I thought it was a typo for “No” and you were contradicting him. Just in case it seemed confusing to him I wanted to emphasize that of course his answer of “c” is correct.