A square based box (length and width = 1m) lies on a horizontal surface on a train. The train decelerates constantly at 5ms^-2 till it stops. Determine the maximum height of the box so that it does not tip over.

Assumptions: - Box does not slide - Equal weight distribution

My answer: the 2 forces providing rotational torque are 1. weight of box acting on the centre of mass and 2. the horizontal deceleration of the object (5ms^-2) also acting on the centre of mass. Taking moments at the pivot point - corner of the box:

Torque of 1. = 9.8M * 1/2 (M=mass of box)

Torque of 2. = -5M * h/2 (h= height of the box)

For the box not to tip:

1.+ 2. = 0

9.8M * 1/2 = 5M * h/2

9.8 = 5 *h

h= 9.8/5 = 1.96 m

Very simple calculation so I am worried it is incorrect...

Thanks in advance for the help.


closed as off-topic by John Rennie, Martin, John Duffield, ACuriousMind, Wolpertinger Aug 27 '16 at 17:53

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Homework-like questions should ask about a specific physics concept and show some effort to work through the problem. We want our questions to be useful to the broader community, and to future users. See our meta site for more guidance on how to edit your question to make it better" – John Rennie, Martin, John Duffield, ACuriousMind, Wolpertinger
If this question can be reworded to fit the rules in the help center, please edit the question.