Projectile Motion Flashcards
What is the only force acting on an object in projectile motion?
Weight force (the force due to gravity). This means the object is only accelerating downwards.
Tips for Projectile Motion.
You can do kinematics in x and y directions separately. Split the velocity vector in to its x and y components.
Tips for Projectile Motion.
No air resistance means the horizontal velocity is constant.
What velocity component is affected by gravity?
Vertical.
What velocity component doesn’t change?
Horizontal
Where does velocity point at the start of the flight?
At an angle to the ground.
Where does total velocity point at the top of the flight?
At the top of the flight gravity has decelerated the vertical component all the way to zero, so the total velocity is flat.
Where does total velocity point at the end of the flight?
At the end of the flight gravity has accelerated the vertical component back to its original length but in the opposite direction.
What is the acceleration of the projectile as it travels upwards?
-9.8ms-2
What formula can you use to solve problems related to the vertical component of velocity?
The kinematic equations, because velocity is constant.
What formula can you use to solve problems related to the horizontal component of velocity?
v = d/t, because the velocity is constant.
What equations can you use to find the horizontal and vertical components of the initial velocity vector?
Soh, cah, toa.
What happens to the force and acceleration during the projectile’s motion?
Nothing happens to the force and acceleration during the motion, since only the force of
gravity is acting on the projectile (which always points downwards and does not change in
size).
What happens to the vertical component of the velocity during the projectile’s motion? Why does this happen?
The vertical component of the velocity is initially large and points upwards, but decreases to zero then continues to decrease to become large and pointing downwards. The cause for this is the weight force since the weight force points downwards the whole time it generates an
acceleration which points downwards the whole time. This causes the vertical component of the velocity to decrease throughout the motion.
What happens to the horizontal component of the velocity during the projectile’s motion? Why does this happen?
Nothing happens to the horizontal velocity during the motion. This is because there are no
forces pointing in the horizontal direction. Since there is no acceleration in the horizontal direction, the horizontal velocity remains constant.
