A ball which is thrown upwards, returns to the ground describing a parabolic path during its flight A. Vertical component of velocity remains constant B. Horizontal component of velocity remains constant C. Speed of the ball remains constant D. Kinetic energy of the ball remains constant

The correct answer is: B. Horizontal component of velocity remains constant

The vertical component of velocity changes because of the acceleration due to gravity. The horizontal component of velocity does not change because there is no force acting on the ball in the horizontal direction.

The speed of the ball changes because the vertical component of velocity is changing. The kinetic energy of the ball changes because the speed of the ball is changing.

Here is a more detailed explanation:

When a ball is thrown upwards, it initially has both horizontal and vertical velocity components. The horizontal component of velocity is not affected by gravity, so it remains constant throughout the flight of the ball. The vertical component of velocity is affected by gravity, so it decreases as the ball rises and increases as the ball falls. The speed of the ball is the magnitude of the total velocity, which is equal to the square root of the sum of the squares of the horizontal and vertical components of velocity. The speed of the ball changes because the vertical component of velocity is changing. The kinetic energy of the ball is equal to one half the product of the mass of the ball and the square of its speed. The kinetic energy of the ball changes because the speed of the ball is changing.