Students work together during an experiment about Newton's laws. The students use a setup that consists of a cart of known mass connected to one end of a string that is looped over a pulley of negligible friction, with its other end connected to a hanging mass. The cart is initially at rest on a horizontal surface and rolls without slipping when released. The inertia of the cart's wheels is negligible. Students have access to common laboratory equipment to make measurements of components of the system.
Students take measurements of the force F0 , directed to the left, needed to hold the cart in place as well as the tension FT in the horizontal section of string. The students take three measurements for each force. Which of the following sets of measurements would provide the most precise determination of the correct relationship between the net force and the vector sum of the individual forces exerted on the cart?