Newton’s Second Law

The purpose of this experiment is to gain a better understanding of Newton’s second law using Data Studio and the Dynamics Track. In this experiment the students will use a fan to propel a cart towards a motion sensor. The data recorded from this experiment will allow the students to measure the acceleration of the cart with different combinations of masses added. The students will confirm the force calculated by measuring it directly with a force sensor. Also, the magnitude of the frictional force on an object at rest, as well as the kinetic friction once that object is brought to a constant velocity will be observed as well. Newton’s second law is the sum of the forces equals mass multiplied by acceleration. Some object with more mass requires a greater force in order to attain the same acceleration as an object with lesser mass. The force used to accelerate the cart is a fan motor; the blades exert a force on the air which exerts an equal and opposite force on the blades. The reaction force is what enables the cart to move forward. Kinetic friction of an object acts in the opposite direction of the velocity of the object; in theory without friction objects would not stop moving once they started.

In the first part of the experiment the students set the cart at the end farthest away from the motion sensor, with the fan propelling air away from the motion sensor. One student turned the fan on while the other presses start to record the data in Data Studio. The cart is released and had to be caught before it hit the motion sensor, then one person presses stop in Data studio. For the graph produced the students had to highlight the points that followed a straight line. The end points were not to be included. The same procedure was done with masses of .2, .4, .6, and .8 kg added to the cart.