Question

At each moment during its flight, a projectile has a velocity v and an acceleration
a. The components of these variables are: vx = x component of the velocity vy = y component of the velocity ax = x component of the acceleration ay = y component of the acceleration which of these components remain constant throughout the motion? Assume that air resistance is absent.

Answer 1

-- There are no horizontal forces on the projectile, so there's nothing acting on it to change its horizontal speed.

ax ... the x-component of its acceleration is zero.

vx ... the x-component of its velocity, is constant.

-- The only vertical force on the projectile is the force of gravity.

ay ... the y-component of its acceleration is constant ... 9.8 m/s²

vy ... the y-component of its velocity DECREASES at the rate of 9.8 m/s/second