Could you help me understand prelab question #1. I need to know what tension is equal to using this. I'm attaching my work to show you where I'm at.

CLASS SET - Please Do Not Write On! FORCES IN EQUILIBRIUM Purpose: To determine the mass of an object that is in static equilibrium. Materials: Sparkvue, Force Sensor, Cart, Ramp, String, Cell Phone Measure App Pre-Lab Questions: 1. Draw the free body diagram for the cart on the ramp. Label all the force vectors in your diagram. 2. From your free body diagram, what is the tension in the string equal to? 3. How do you calculate the mass of an object when you know the weight? Procedure: 1. Set the ramp at an angle of 150 to start. (Use the Measure app on your iphone to determine the angle of the ramp). Connect the force sensor to your computer using the airlink. Make sure the string is parallel to the track. 2 . Open up Sparkvue on your computer and choose 'Sensor Data'. When it reads the force sensor, choose 'Force, Pull Positive'. Choose Digits. 3. Once the experiment is open and you see a digit screen (It should read ON), click on the tools icon on the bottom right. Click 'Data Properties' then under 'Number Format' you should be able to change the number of digits visible. Change that to 4 and click ok. 4. You should be back on the digits screen. Push the cart up the ramp so there is NO tension in the string and press the 'zero' button on the force sensor. This will calibrate the force sensor. 5 . Gently release the car back to its original position. Press start to read the tension force in the string. Record this value and then hit stop. 6. Repeat steps 4 and 5 for 2 more angles. You should adjust the angle by at least 50 (either way) each time. Data and Results: 1. Create a data table for your three trials to show the angle of the ramp and tension force in the string. 2. Use your data for the tension force and the angle of the track to determine the weight (the gravitational force) of the cart for all 3 of the angles. Show ALL of your work. 3. Calculate the mass of the cart for all 3 angles and average them. 4. Find the actual mass of the cart using a balance. Determine the percent error between your average calculated mass and the actual mass. (Look up the formula for percent error if you do not remember how to do it)