Circular Motion

Question 1

When a string with mass is moving hirosntslly, why can it never actually move in perfect horizontal circle ?

So why is their approximation if at high speed tension = centripetal

Answer 1

This is because there had ti be some angle such that vertical component of tension BALANCES weight . THUS THE ANGLE WILL NEVER BE 0°

When going at high speeds the angle is very small. Here the resultant for tension is mv2/r squared + mg sqaured all sqaure root

At high speeds the mg component will barely do anything to equation so approximation is excluding it

And when tension that high at high speeds, the vertical force can be balanced even with a small anb,e

Question 2

So in spinning horitnsl question how to find tension roughly?

Answer 2

Mv2/r, I guess ignore everything else and think whole tension force is acting here so