Motion of Projectiles

In Physics we are still talking about projectile motion. A projectile is something that has movement on the two different axes, y and x axes. The motion of a projectile, or projectile motion, is a type of 2D kinematics. This means that kinematics, the branch of physics concerning motion, is happening on two different dimensions. The picture below is of my friend Christian right after getting some “sick air” while we were skating one day. He was a projectile the moment his board left the ground, because he was moving through the air without any other forces but gravity affecting his movement. He was also moving in a parabolic motion from the top of the stairs to where he landed.

If the stairs were 1 meter high, and Christian landed 2 meters from where he took off, and he was in the air for 2.5 seconds, we can use equations like “dat” to find his initial Velocity(x). These are our givens, along with a y-acceleration of 9.8m/s² because of gravity.

X		Y
2m	=D=	1m
0m/s2	=A=	9.8m/s2
2.5s	=T=	2.5s
	=V=
?	=V0=	0m/s

D_x=1/2a_xt²+V_oxt

2m=1/2(0m/s²)(2.5s²)+V_ox(2.5s)

2m=V_ox(2.5s)

V_ox=0.8m/s

Using “dat_x” equation, and my assumed givens, I was able to find out that Christians initial velocity in the “x” direction was 0.8m/s.