Does this make sense? Something hanging from an accelerating object

[Cheeseburger]

Homework Statement

A pair of fuzzy dice is hanging by a string from your rearview mirror. While you are accelerating from a stoplight to 28m/s in 6s, what angle does the string make with the vertical?

Homework Equations

g, accel. of car is 4 2/3 m/s^2

The Attempt at a Solution

http://img505.imageshack.us/img505/8594/physwl0.png

I just figured the two accelerations were all that was necessary since the string length and mass are not given. So the angle is arctan(4.66/9.8) or 25.43 degrees? I did this in class in under a minute and it seems right but on the other hand it also seems too easy.

 

[mgb_phys]

Yes it is that easy (assuming your arithmatic is correct)