Centripetal force

hi i am really stuck on understanding the velocity and acceleration of an object in circular motion.
the questions is to describe the velocity and acceleration of a balls both before and after the spring breaks.

Hi @anne,

I hope this diagram helps you to follow the points below:

circular motion

Any object in circular motion has a unbalanced (or net) force acting on it. This unbalanced force is directed towards the centre of the circular path. Since the object has mass, and is acted upon by an unbalanced force, it must accelerate in the direction of the unbalanced force (according to Newton’s second law). This is shown by the equation uF=ma (I’ve added the ‘u’ to remind us it is an unbalanced force).

We can hopefully see that the object must accelerate towards the centre, as that is the direction of the unbalanced force.

At Level 2 we only deal with uniform circular motion, which means the speed of the object does not change. However, since the definition of acceleration is a ‘change in velocity over time’, we know the velocity must be changing. Recall that velocity is a vector quantity, meaning it has size and direction. The size (speed) stays the same but the direction of the objects velocity is changing with it’s position around the circular path. At any stage of it’s circular path, if you remove the centre seeking (centripetal) force, the object will continue according to its velocity at the instant the force is removed. We describe the direction of this velocity as being tangential.

I’ve prepared a short video explaining how I would approach a similar question.

thank you that helped a lot thanks.

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