need help asap?

Question

suppose you tie a rock to the end of a 1meter long string and spin it in a vertical circle.wat is the minimum speed it can travel and just get around the top?(the rope will just start to go slack and the only force acting on the rock,downward,is gravity)

Answer 1

Fc = mv^2/r
= m(v^2)/1
= mv^2 N

Fg = mg N

set equal to each other, m cancel out

v^2 = g = 9.81
v = sqrt(9.81)
v = 3.13 m/s

Answer 2

you might need to pick a lighter rock.
or
you might need to tie the rock on the string tighter
or
if you can use less string, then I would do that


Hope this helps. Good Luck