Physics Lab Newtons 2nd Law

[FrankP]

Hello so I am having an issue with rectifying the math for this problem. I have the answer that my teacher gave me which is the answer specific to my lab but on my own I can not prove the math to be correct. I actually cant even get a number at all my calculator is giving me a constant error.  

 

Background on the problem: Car attached to a string with a mass suspended on it passes through a photo-gate connected to a smart timer which reads the acceleration. These trials are performed on an incline ramp which has an unknown angle of incline. This is the problem we want to figure out besides tension and all that we want to determine what the angle of the incline is based on the information given. I have worked this math more than 20 times and I have yet to get a single answer. 

 

I am going to send a picture of the equation I am supposed to be using as well as the number that the angle is supposed to work out to be. 

• a = acceleration (average) 
• M = mass of car with string
• m = mass suspended on end of string
• g = gravity (standard 9.8)

 

thank you guys in advance I cant figure why this is giving me issues. 

 

Edited October 24, 2017 by FrankP

[OldChemE]

If your calculator is giving you an error, check settings.  Most good calculators can do angles in degrees or radians.  If you have it in the wrong mode (radians when you want degrees, or vice versa) it will make results come out wrong.

[FrankP]

 The calculator is in the proper mode I checked that first. Something is wrong with the math not the calculator I am just not able to figure out what is wrong with the math hence my inquiry. I have asked my lab teacher as well who does not respond to emails so as expected 2 weeks no response.