I have two equations:

#1)
Tcos(theta)- 6.86=0

#2)
Tsin(theta) = mass X acceleration

I know that my acceleration is velociy squared/ radius (my given radius is 40cm)

I'm supposed to solve for T and angular acceleration. I know I'd be able to do that if I could find what theta is. Can you give my instruction on how to find theta? (just how to find theta, I want to solve the rest of the problem on my own.)

thanks

T=6.86/cosTheta

6.86/cosTheta*sinTheat= ma
tan theta= ma/6.86
solve for theta. Now go back and solve for T

To find theta, you can use the first equation:

Tcos(theta) - 6.86 = 0.

To isolate theta, you will need to rearrange the equation:

Tcos(theta) = 6.86.

Next, divide both sides of the equation by T:

cos(theta) = 6.86 / T.

To find theta, take the inverse cosine (cos^-1) of both sides of the equation:

theta = cos^-1(6.86 / T).

Now, you have a formula to find theta given the values of T and 6.86.