# Vertical Projectile Motion

Projectile motion is the study of objects in free fall.

*Projectile motion or vertical projectile motion is a study of objects in free fall*. In understanding this topic, prior knowledge of grade 10’s rectilinear motion and grade 11’s functions is required

This section of physical sciences is concerned with the calculation of velocity at which objects are released or hit the surface. In addition, you will be required to calculate the distance the object has travelled upon release or its displacement after some time.

To pass the questions of this topic, you will need to:

- Apply equations of motion to calculate velocity, time and displacement of objects.
- Interpret and draw:
*velocity vs. time graph*,*position vs. time graph*and*acceleration vs. time graphs*.

In addition, you will be required to apply the knowledge gained in this topic to other topics like momentum and impulse; forces; and work, power and energy. You should therefore not be surprised when you see a projectile motion topic in these topics or vise versa.

Some of the terms used in the topic:

Free fall: motion of an object in the absence of air resistance, where only gravity influences the object.

Projectile:object or particle that is projected or launched and then moves only under the influence of gravity.

To solve the problems of projectile motion and quantify how much velocity is used, how much time is spent in the motion and how long is the distance travelled by the projectile, we make use of equations of motion:

\begin{alignat} {1} v_f &= v_i +a\Delta{t} \tag{1} \\ v_f^{2} &= v_i^{2} + \frac{1}{2} a \Delta{t^2} \tag{2} \\ \Delta{y} &= v_i\Delta{t} + \frac{1}{2}a\Delta{t^2} \tag{3} \\ \Delta{y} &= (\frac{v_1+v_f}{2})\Delta{t} \tag{4} \\ \end{alignat}We will show you to apply these equation in the next lesson. stay tuned!!