How Can the Tension in a Cord Without Mass Be Found?

[pharoh123]

Homework Statement

While in a car, a rubber ball is suspended by a cord. When the car slows down, the ball forms a 13 degree angle. Find the acceleration of the car when it is slowing down and the tension in the cord.
I found the acceleration of the car, which is 2.3 m/s² easily but when i try to find the tension, i am left with the unknown on the numerator of both sides of the equation and i can`t go further.

Homework Equations

In Y
T_y=mg
T*cos x=mg
m=(T*cosx)/g
-------------------------------------
In x
T_x=ma_x
T*sinx=ma_x
m=(T*sinx)/a_x
----------------------------------
m=m
(T*cosx)/g=(T*sinx)/a_x
what do i do now?

The Attempt at a Solution

see above

 

[Doc Al]

You won't be able to solve for the tension without knowing the mass of the ball.

 

[pharoh123]

You won't be able to solve for the tension without knowing the mass of the ball.

i thought so too because the question asks you if it is actually possible to find the tension without the mass. I answered no but in the book`s answer key, there`s actually an answer (it`s 0.25N).