Researchers have shown students develop misconceptions in projectile motion for various reasons. A common misunderstanding among first-year high school physics students is the notion that the horizontal and vertical components are interchangeable in projectile motion. The students' incorrect reasoning is connected to their personal experiences when they claim a heavier object will reach the ground before a lighter object when dropped from the same vertical height. When the students are asked about two objects projected horizontally with different speeds from the same height, they will quickly assume that the faster horizontal moving object will hit the ground first, reasoning that the horizontal speed directly affects the vertical speed. The students fail to notice that the initial vertical velocity equals zero.