# Answers to Conceptual Questions on Projectiles in Physics

Answers to true or false conceptual questions on projectiles in Physics and equations of a projectile .

A projectile is launched. Assuming that air resistance is negligible, which of the following are true?

## Answers to conceptual questions on projectiles in Physics

A. Any object upon which the only acting force is the force of gravity is called a projectile.
TRUE : Definition

B. The projectile problem involves constant velocity along the horizontal direction and constant acceleration along the vertical direction.
TRUE : see equations of velocity and acceleration of projectile

C. The vertical component of the velocity of the projectile is constant.
FALSE : see equations of velocity of projectile.

D. The horizontal component of the velocity of the projectile is constant.
TRUE : see equations of velocity of projectile.

E. The acceleration is constant.
TRUE : see equations of acceleration of projectile

F. The kinetic energy of the projectile is constant.
FALSE : The magnitude of the velocity of a projectile is not constant, therefore its kinetic energy is not constant.

G. The potential energy of the projectile is constant.
FALSE : The height of the projectile changes and therefore the potential energy due to gravitation in not constant.

H. The sum of the kinetic and potential energies is constant.
TRUE : The total mechanical energy is constant.

I. The minimum speed of the projectile is equal to horizontal component of the velocity of the projectile.
TRUE : The velocity has two components: Vy and Vx. Vx is constant and Vy is a function of time and may be zero.

J. The horizontal component of the velocity of the projectile varies linearly with time.
FALSE : It is constant.

K. The horizontal component of the displacement of the projectile varies linearly with time.
TRUE : x = Vx t (see equations of displacement of projectile)

L. The vertical component of the displacement of the projectile varies linearly with time.
FALSE : y = Vy t - (1/2) g t 2 (see equations of displacement of projectile)

M. The path of a projectile is a parabola.
TRUE : See equation of the path of a projectile.