
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?
 Any object upon which the only acting force is the force of gravity is called a projectile.
TRUE: Definition
 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
 The vertical component of the velocity of the projectile is constant.
FALSE: see equations of velocity of projectile.
 The horizontal component of the velocity of the projectile is constant.
TRUE: see equations of velocity of projectile.
 The acceleration is constant.
TRUE: see equations of acceleration of projectile
 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.
 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.
 The sum of the kinetic and potential energies is constant.
TRUE: The total mechanical energy is constant.
 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.
 The horizontal component of the velocity of the projectile varies linearly with time.
FALSE: It is constant.
 The horizontal component of the displacement of the projectile varies linearly with time.
TRUE: x = Vx t (see equations of displacement of projectile)
 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)
 The path of a projectile is a parabola.
TRUE: See equation of the path of a projectile.

