Question

during projectile motion, the quantities which remain constant are?

Answer 1

vertical acceleration and horizontal velocity

Answer 2

Projection motion is a two dimension motion...If you throw any object other than verticle is a will be projectile motion...

The path in which an object moves is called its trajectory and Its trajectory is parabollic..

Actually Projectile motion is a combination of two motion...One is Horizontal and Other is Verticle..

When we throw any object with velocity v making an angle x with horizontal...then the resultant vector of velocity can be resolve into its component as Verticle and Horizontal..

The Horizontal component i.e, vCoSx is Constant throughout the motion...
The Verticle Component i.e, vSinx is Variable...it changes as Altitude(Height) changes

so Horizontal Velocity is constant througout the projectile motion...