A 0.90 kg rock is attached to a 0.35 m rope and spun in a vertical circle. The tension on the rope when the rock is at the top of the swing is 76.0 N [down]. What is the speed of the rock?

Question

A 0.90 kg rock is attached to a 0.35 m rope and spun in a vertical circle.  The tension on the rope when the rock is at the top of the swing is 76.0 N [down].  What is the speed of the rock?

abhisar · Answer

do u know about free body diagrams ?

anonymous · Answer

i know what they are but not how to draw them and apply them

anonymous · Answer

76 + 0.90*9.81 =[{ 0.90*(v^2)}/0.35] or 
v^2 = (0.35)*[{(76)/0.90} + 9.81] = 94.25 or v = 9.7 m/s

anonymous · Answer

im on a limited time schedule to finish some questions so can u please tell me ASAP whether or not tha above work is correct @Abhisar

abhisar · Answer

not sure !

abhisar · Answer

but i think it's correct !