# What affects tangential acceleration and normal or c?

1. Dec 1, 2012

### Lenjaku

I was wondering if acceleration (a) is the speed in which speed changes how come it can b higher than 0 and still v=0?

like when there is a force pulling from the other side, the body won't move but since there is force there is acceleration.

So which is which?
Does the tangential acceleration affect the angle of the velocity vector?
and its size the speed in which the speed would change?
then what does the normal acceleration does?

It was clear at first but after solving some problems I got confused -.-

2. Dec 1, 2012

### rcgldr

Acceleration only occurs when there is a net force on an object. If sum of all the forces (treated as vectors) acting on an object equals zero, then there is no net force and no acceleration.

3. Dec 1, 2012

### grzz

One must look at the net i.e. the resultant force acting on the body.

If this resultant force is zero then the acceleration must be also zero.

4. Dec 1, 2012

### Lenjaku

I had a problem where I had static friction and force in opposite directions and I had to find the time in which the object will start moving (while the force was represented with t for time).
So I went ahead and found the max static friction and found the time needed but when I tried the t I found in the general equation of ma I got a positive number.
Teh t I found works for

The force worked on another object which was tied to this 1 with idialistic rope.

-fs+T=ma
a turns to be 0.

(T for tension)

But then why the x component won't be 0 when I calculate it with t?
this is teh equation:
a(t)=0.8163*t-2.64

And there is this equation:
-fs+T=ma
T=3.63636*t
then : fs=T
fs=15.68
so t=4.31

a turned to be:0.8163*t-2.64

I don't get why it is not a 0...
a(t=4.31)=0.8163*4.31-2.64=0.878.....

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Last edited: Dec 1, 2012
5. Dec 1, 2012

### lep11

Could you please clarify your post and original question a little bit?
Normal acceleration and tangential acceleration are related to rotational movement.