# Tangential Acceleration

1. Dec 31, 2012

### heartyface

1. The problem statement, all variables and given/known data
Perhaps I am confused by the concept.
A toy car starts from rest at a height 4R above the ground and continue to a loop of radius R (frictionless). At a point C (height R from the ground) inside the loop, what is the tangential acceleration of the toy car?

2. Relevant equations

I don't think a=alpha*r is quite relevant to this...or a=dv/dt...

3. The attempt at a solution
not quite yet. perhaps the gravity is the only thing?

Please, explain me of the concept of 'tangential acceleration' and its components.

2. Jan 1, 2013

### haruspex

Tangential acceleration is simply the component of linear acceleration that's in the tangential direction. You are right that this is not the same as angular acceleration * radius, $r\dot{ω}$. There is also the Coriolis term $2\dot{r}ω$.
It's not quite clear from the question (the position of the loop in relation to the ground is not given): is point C where the loop is vertical?

3. Jan 1, 2013