Componet of velocity perpendicular to plane at the time of projection is sameas the component of velocity perpendicular to plane when it strikes the ground (inoppositedirection)

usin30=20sin30

usin30=20sin30

=10m/s

=10m/s

*Additional information*

A body which is in flight through the atmosphere under the effect of gravity alone and is not being propelled by any fuel is called projectile.

Assumptions of Projectile Motion

i. There is no resistance due to air.

ii. The effect due to curvature of earth is negligible.

iii. The effect due to rotation of earth is negligible.

iv. For all points of the trajectory, the acceleration due to gravity ‘g’ is constant in magnitude and direction.

Principle of Physical Independence of Motions

(i) The motion of a projectile is a two dimensional motion. So, it can be discussed in two parts. Horizontal motion and vertical motion. These two motions take place independent of each other. This is called the principle of physical independence of motions.

(ii) The velocity of the particle can be resolved into two mutually perpendicular components. Horizontal component and vertical component.

(iii) The horizontal component remains unchanged throughout the flight. The force of gravity continuously affects the vertical component.

(iv) The horizontal motion is a uniform motion and the vertical motion is a uniformly accelerated or retarded motion.

And There are Three types of Projectile Motion

a. Oblique projectile motion

b. Horizontal projectile motion

c. Projectile motion on an inclined plane