Question

Distinguish clearly between distance and displacement of a projectile.

Answer 1

Hint: The trajectory of the projectile motion has many physical quantities involved and distances the space between two points and displacement the minimum distance between two points exists.

Complete step-by-step answer:
Projectile: A body which is in flight through the atmosphere under the effective gravity alone and is not being propelled by any fuel is called projectile and its motion is called projectile motion.

Some examples of projectile motion:
1. A bomb released from an airplane in level flight
2. A bullet fired from a gun
3. An arrow released from bow
4. A javelin throw by an athlete
Distance can be generally defined as the measurement of how far apart are two points in space.
In case of motion distance is the measure of length travelled by any object.
Distance is the length travelled by the body in motion which means that the length of the parabolic arc created by the projectile is the distance whereas the displacement is the gap between the two points that are starting and end points.
\[
  x = ut\cos \theta \\
  y = ut\sin \theta - \dfrac{1}{2}g{t^2} \\
\]
And the magnitude of the displacement of the projectile is given by $\Delta r = \sqrt {{x^2} + {y^2}} $ .

Note: In projectile motion horizontal component of velocity, acceleration and mechanical energy remains constant while speed, velocity, kinetic energy and potential energy changes.