The Calculations
We are are repeatdly applying the constant acceleration equations to get updating values for the horizontal and vertical
displacement and the vertical velocity. Note, horizontal velocity is constant since there is no horizontal acceleration.
We will use the following SUVAT equations to update out position and velocity:
$$\small{ s_x = v_x \times t }$$ $$ \small{ s_y =u_y \times t - \frac{1}{2} \times -9.81 \times t^2 }$$ $$ \small{ v_y = u_y - 9.81 \times t }$$
The inital conditions for this projectile are given by (chosen by you!):
Initial height: , Initial Vertical Velocity: = u,
Initial Horizontal Velocity:
So we can calculate the new x position s
Also we can calculate the new y position s m
Finally, we can calculate the new y velocity v m/s
Where s is the horizontal position, s is the vertical position,
v is the horizontal velocity, v is the vertical velocity,
u is the initial vertical velocity, and t is the time since launch.
We can also calculate the vertical & horizontal range and the time of flight:
Now check your understanding by calculating the vertical and horizontal range! (round your answers to the nearest whole number)
Note, as with all projectile motion examples we are making a lot of assumptions: (1) there is only vertical acceleration which is gravity (2) we are taking the earth as flat (3) each axis is a 'wall' (4) the particle does not bounce