Finding Maximum Tension in a String

[Andriko]

This is a question in my physics lab I'm pretty sure i have done it wrong but don't know what. if anyone can help that would be great

Q- Determine the maximum tension in a string 3m long, supporting a mass of 2Kg, if its released at an angle of 30 degrees to the vertical. (assume vacuum)

The first thing i did was find Fg which is m*g, which equals 2Kg*9.8 =19.6

Then i made a relationship with the angle to find the force of tension which i believed to be the hypotenuse?

Ft = 19.6/sin(30)
= 39.2 N ?

 

[JustinLiang]

You mean the tension in the string at that point?

The maximum tension of the string can be found at the bottom of the swing due to teh force of centripetal acceleration.

But to find the tension force at that point when it is 30 degrees from the vertical would be 19.6cos30, you have the adjacent force which is the force of gravity so you have to find the hypotenuse.

 

[Andriko]

Oh i understand i think i did a sin error, rather then doing cos i did sin