NEET Physics: Projectile Motion Practice Questions

Correct answer: C — v₀ sin θ

The initial vertical component of the velocity (v₍0y)) is calculated using the sine of the launch angle (sin θ), i.e., v₍0y) = v₀ sin θ.

Correct answer: C — Gravity acting downwards

The only force acting on the body during free fall is gravity. Therefore, the acceleration is the acceleration due to gravity (g), directed downwards, regardless of the initial state of motion or the height of the cliff.

Correct answer: A — u/2

When a projectile is launched vertically upwards, its velocity decreases until it momentarily stops at the highest point. Therefore, the velocity at the highest point is zero.

Correct answer: C — 1/2gt²

Since the motion is purely vertical under constant acceleration (g), the vertical distance covered is given by h₍fall) = 1/2gt², where h is the initial height and t is the time of flight.

Correct answer: A — They will hit the ground simultaneously

In the absence of air resistance, the acceleration due to gravity is the same for all objects, and they start with the same initial velocity (zero). Therefore, they will reach the ground at the same time simultaneously.

Correct answer: C — The horizontal velocity is constant and equal to uₓ

In projectile motion (ignoring air resistance), there is no acceleration in the horizontal direction. Thus, the horizontal velocity (vₓ) remains constant throughout the entire flight.

Correct answer: D — Constant velocity (assuming no air resistance)

In projectile motion, if we ignore air resistance, there are no horizontal forces acting on the object. Therefore, the horizontal velocity remains constant, meaning the horizontal acceleration is zero.

Correct answer: B — g (upwards)

At the highest point of the trajectory, the projectile momentarily stops before changing direction, but the acceleration due to gravity (g) is still acting downwards.

Correct answer: A — Zero

At the maximum height, the instantaneous vertical velocity of the object becomes zero, even though the acceleration due to gravity is still acting upon it.

Correct answer: C — 45°

For a fixed initial velocity, the horizontal range (R) is maximum when the angle of projection (θ) is 45°.

Correct answer: C — 2gT

The total vertical distance covered during the time of flight is determined by the displacement, which is h = 1/2 g T². However, since the question implies the distance covered *during* the flight, and assuming the motion is symmetric (dropping from rest), the total distance covered is 2 × (maximum height) = 2 × (T/2) × g = gT. (Correction: The phrasing implies the total distance covered. For a symmetric trajectory starting from rest, the distance covered is gT.)

Correct answer: D — T = 2H

For a projectile launched and landing at the same level, the time taken to reach maximum height is half the total time of flight (tᵤₚ = T/2). The kinematic equations relating T and H (assuming launch from ground) are dependent on the initial angle and velocity, but the relationship derived from time symmetry is T = 2tᵤₚ and H is determined by the vertical velocity. However, for simple conceptual recall, we establish the fundamental relationship based on the symmetrical nature of the path when launched and landed at the same height. In basic problems, if we consider time symmetry, the vertical motion implies a direct relationship, but the primary conceptual check here is recognizing that T is the total duration and H relates to the peak vertical motion. (Note: For a general launch, this relation is complex, but in basic conceptual tests, often the relationship derived from symmetrical time is tested.) The correct conceptual relationship derived from v_y = 0 at the peak is that the time is symmetric.

Correct answer: B — g downward

The acceleration experienced by a projectile is solely due to gravity, which acts vertically downwards. The horizontal acceleration is zero because there are no horizontal forces acting on the projectile once it is in the air (neglecting air resistance). Therefore, the acceleration is g (downward).

Correct answer: B — Constant throughout the flight

In the absence of air resistance, the horizontal velocity remains constant because there is no horizontal force acting on the projectile (acceleration in the x-direction is zero).