Ideal speed given radius and angle

[Mariesa Yeoman]

Homework Statement

What is the ideal speed to take a 70 m radius curve banked at a 30.0° angle?

Homework Equations

tan θ = v²/r g

The Attempt at a Solution

This has me stuck, when I attempted this I came to the equation v= √ g*r* tan Θ
But when I substitute in the variables, I enter then into the calculator and it show answer undefined? Is this not the correct formula? or am I simply doing it wrong?

 

[kuruman]

It has nothing to do with the formula. Be sure your calculator is set to degrees. In radians tan(30) is negative and trying to take the square root of that will cause an error.

 

[Mariesa Yeoman]

I guess I am just unsure of how to do the problem?

 

[haruspex]

I guess I am just unsure of how to do the problem?

I would say @kuruman has almost surely identified what you are doing wrong.
Do you not know how to set your calculator to degrees instead of radians? If so, enter the angle in radians. 30° is π/6. Its tan should be 1/√3, about 0.5774.

 

[Mariesa Yeoman]

Ok that took care of it, Thank you so much!