You and your classmates are experimenting with the pull of gravity on falling objects. You know from science class that if no air resistance is present, the rate of descent depends only on how far the object has fallen, no matter how heavy the object is. This means that two objects (a bowling ball and a pen) will reach the ground at the same time if they are dropped simultaneously from the same height. After multiple trials, objects continued to hit the ground at the same time when dropped from equal height, until the last trial. In the last trial, Hannah and Annie dropped an expo marker, a paperclip, and a notecard. The paperclip and the marker reached the ground at the same time, but the notecard was slower. What statement best explains their findings? A) The downward force of gravity is less on the notecard because it has less mass. B) The upward force of friction is greater on the notecard than the other objects. C) The upward force of air resistance is greater with the notecard causing it to reach the ground slower. D) There was an error in the experiment. All of the objects will reach the ground at the same time due to equal gravitational pull.