A projectile moves under the combined effect of two velocities. 

• A uniform velocity in the horizontal direction, which will not change provided there is no air resistance. 
• A uniformly changing velocity (i.e., increasing or decreasing) in the vertical direction.

There are two types of projectile motion: 

• Projectile given an initial velocity in the horizontal direction (horizontal projection) 
• Projectile given an initial velocity at an angle to the horizontal (angular projection)

 There are two types of projectile motion:

• Projectile given an initial velocity in the horizontal direction (horizontal projection) 
• Projectile given an initial velocity at an angle to the horizontal (angular projection)

 To study the motion of a projectile, let us assume that,

• Air resistance is neglected. 
• The effect due to rotation of Earth and curvature of Earth is negligible. 
• The acceleration due to gravity is constant in magnitude and direction at all points of the motion of the projectile.