projectile theory (1 Viewer)

[c0okies]

hi this is a concept thing i really dont get and cant find in the theory...

can someone explain to me why tan β = y' = y(dot)/x(dot)
because its in the solutions but i really dont understand where it came from

by the way, β is any angle made by the tangent to the curve and the horizontal

thanks ahead

 

[Riviet]

At any point on the trajectory of the projectile, there will always be a vertical and horizontal component to the projectile's velocity, whether it be positive, negative or zero. If you draw a triangle using the tangent, a horizontal line that cuts that point horizontally and dropping a perpendicular to that horizontal line, you should be able to identify that β is one of those angles in the triangle formed.

.'. tanβ = vertical component of velocity at that instant / horizontal component of velocity at that instant

=
.
y
_
.
x

I hope that helps.

 

[c0okies]

ohh i get it now.. thanks! =)