How Do You Calculate the Tension in a String During Circular Motion?

[azncocoluver]

Homework Statement

A 0.55 kg stone attached to a string is whirled in a horizontal circle of radius 19 cm as in the figure below. The string makes an angle of 35° with the vertical.

Homework Equations

The Attempt at a Solution

 

[tiny-tim]

hi azncocoluver!

show us what you've tried, and where you're stuck, and then we'll know how to help!

(oh, and what actually is the question asking for? )

 

[azncocoluver]

Haha wow, I totally forgot to put the question.
(a) Find the speed of the stone.
m/s

(b) Find the tension in the string.
N

I have no idea where to start. :[

 

[tiny-tim]

hi azncocoluver!

nearly all dynamics questions boil down to good ol' Newton's second law (F = ma) …

so the first step is to draw a diagram with the forces and acceleration labelled,

and the second step is to write out the equation …​

what do you get?

 

[azncocoluver]

Ft = Fg?

 

[tiny-tim]

where's the acceleration (and the angles)?

 

[azncocoluver]

No clue lol.. can you show me the solution because I've never done a problem like this before. I kind of learn better when I see an approach first :]

 

[Mark44]

No clue lol.. can you show me the solution because I've never done a problem like this before. I kind of learn better when I see an approach first :]

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