Parabolic motion
Let’s think about the motion of throwing an object horizontally.
There is no horizontal force when there is no air resistance, so there is no change in speed.
![](/lee/contents/clay_shooting_image1.png)
This time, let’s consider a dropping.
If the initial velocity is ‘0’, the motion that falls vertically is called the free-fall motion. Earth’s gravity is acting in the vertical direction, so a change in speed occurs. In other words, It does ‘accelerated motion.’
Due to the Earth’s gravity, the object accelerates toward the center of the Earth.
![](/lee/contents/clay_shooting_image2.png)
Assuming that an object is dropped from a moving airplane, it moves linearly at constant velocity in the horizontal direction and free-fall in the vertical direction.
The final motion can be obtained by combining the motion in the horizontal direction and the motion in the vertical direction.
![](/lee/contents/clay_shooting_image3.png)
![](/lee/contents/clay_shooting_image4.png)
What if you throw an object up with an angle?
![](/lee/contents/clay_shooting_image6.png)
When an object is thrown up with an angle, the only force exerted on the object is gravity, and it moves at a constant velocity in the horizontal direction, resulting in a parabolic orbit.
![](/lee/contents/clay_shooting_image7.png)