Several common misunderstandings can lead to incorrect calculations in projectile motion. Let's clarify some of them.
Misconception: Heavier objects fall faster.
In a vacuum, all objects fall at the same rate regardless of their mass. This calculator, like most introductory physics models, assumes a vacuum by ignoring air resistance. In reality, air resistance can affect lighter, less aerodynamic objects more significantly, but for many dense objects, this model is a very good approximation.
Misconception: A 45° launch angle always gives the maximum range.
This is only true when the launch and landing heights are the same. If an object is launched from a height, the optimal angle for maximum range will be less than 45 degrees. Conversely, if launching from the ground to a target at a greater height, the optimal angle will be greater than 45 degrees.
Misconception: Horizontal and vertical motions are dependent.
A key principle of projectile motion is the independence of motion components. Gravity only affects the vertical velocity; it has no effect on the horizontal velocity. This allows us to analyze them separately, which simplifies the problem significantly.