Students should have a strong conceptual understanding of the connection between force and acceleration before they start working with applications and problem solving. This has been discussed in the literature. During these days of flipped classroom instruction, an at-home activity could be especially valuable. I will describe an experiment with very simple equipment that students could do on their own. To give students a feeling of the connection between force and acceleration, it has been quite common to let them draw blocks or carts across the table with a rubber band or a metal spring. But keeping the rubber band or spring at constant length can be quite a challenge. Instead I was looking for some kind of dynamics cart track made from very simple equipment that students have at home.