Calculating Net Force on a Spinning Ball

[synergix]

Homework Statement

Mass of ball=0.500kg string length=1.02m
I have a motion diagram of a ball being spun in a counter clockwise direction. there are four points on the circular diagram this is the best I can do right now

......v= 4.0m/s
......|
......|
v=6.0m/s ---------- v= 6.0m/s
......|
......|
...v=7.5m/s

calculate the value(in N) of the net force at the top point. What law are you using?

The Attempt at a Solution

I know how to calculate if their is tangential + radial acceleration but If anyone could explain why there would or would not be tangential acceleration at the top and bottom point of the swing that would be very helpful because I am not sure. I am leaning towards using just the force of gravity on the ball for my final answer.

 

[tiny-tim]

I know how to calculate if their is tangential + radial acceleration but If anyone could explain why there would or would not be tangential acceleration at the top and bottom point of the swing that would be very helpful because I am not sure. …

Hi synergix!

From the symmetry, the speed must be at a minimum or maximum at the top or bottom, so the tangential acceleration will be zero.

 

[synergix]

Thank you very much! Tiny Tim :) But their would be tangential acceleration up until the instant it reached the top or bottom right?

 

[tiny-tim]

Yup!