The diagram below represents a student using a spring scale to pull a toy cart across a level table. The student pulled the cart across the table five times. Each time, the student used more force. Force is measured in newtons (N) on the spring scale. The student then calculated the acceleration of the cart, measured in meters per second squared (m/s2). The results are shown in the data table. Determine the mass of the cart. Show all your work. Please include all units.