Q:

Freefall to circular motion?

So I want to make a game with grappling hook but sadly I don't know physics. The question is 

Circular motions force direction is always perpendicular to Radius?
When freefall into circuler motion happen how velocity will change?(when rope is change to tight) And How do i google it i don't know how to call this thing.

A:

To answer your first question, yes. Circular motion always has the force component perpendicular to the velocity. The role of the centripetal force is to change the direction of the body at every instant.
Now, when the string becomes taught, the behavior is just like a pendulum and energy is conserved. Hence you can find the velocity at any height by equating the energy to the initial potential energy.

