# Property of for same acceleration

1. Jul 4, 2015

### andyrk

Does the property that two bodies connected together and if one of them is accelerating with some acceleration the second also accelerates with the same acceleration, have a name? Like for example, if there is a person in an elevator and the elevator is accelerating with acceleration $a$, then the person also accelerates with acceleration $a$. Is there a name for this property? Or is not a property because it is so logical that it is said so because it makes sense?

2. Jul 4, 2015

### Dr. Courtney

When to masses are connected with a rope or string, the condition is that the rope or string not stretch.

More generally, there needs to be a fixed distance and orientation between the two objects the for their acceleration to be the same.

3. Jul 4, 2015

### andyrk

What about the case for a person inside an accelerating elevator?

4. Jul 4, 2015

### Staff: Mentor

It is called rigid motion or, in relativity, Born rigid motion.