Question

The trajectory of projectile is

• A. Semicircle
• B. An ellipse
• C. A parabola always
• D. A parabola in the absence of air resistance

Answer 1

The Correct Option is D

1. Understand the Concept:

A projectile follows a curved path under the influence of gravity. The nature of the trajectory depends on the initial velocity and the absence or presence of air resistance.

2. What Happens in Ideal Conditions (Absence of Air Resistance)?

In the absence of air resistance, the trajectory of a projectile is influenced only by the gravitational force acting vertically downwards. The motion can be broken into horizontal and vertical components:

• The horizontal velocity remains constant, and the horizontal displacement increases uniformly.
• The vertical velocity changes due to gravity, leading to an upward and then downward path.

When we combine these motions, the result is a parabolic trajectory.

3. Examine Each Option:

• (A) Semicircle: A semicircle is not a correct option. This shape would be true only in specific cases, such as when the projectile is launched straight upward and falls back down.
• (B) Ellipse: An ellipse is the path followed by an object in orbital motion under the influence of gravity (like planets around the Sun), not a typical projectile motion.
• (C) A Parabola Always: This is incorrect because, in the absence of air resistance, the trajectory is always a parabola, but the term "always" doesn't make sense in other contexts like circular or elliptical motion.
• (D) A Parabola in the Absence of Air Resistance: This is the correct statement. The trajectory of a projectile is a parabola when air resistance is negligible.

4. Final Answer:
The trajectory of projectile is A Parabola in the Absence of Air Resistance

Answer 2

The trajectory of a projectile is the path it follows during its motion. While a projectile's trajectory may resemble other shapes in certain specific situations, the most accurate and general description is that it follows a parabolic path in the absence of air resistance. Options (A) and (B) are incorrect as they describe different geometric shapes. Option (C) is incorrect because the presence of air resistance can distort the parabolic path.

The correct answer is (D) a parabola in the absence of air resistance.