# A question and no idea what to do

ouse
determine the inital velocity of a projectile that is luncked horizantaly and falls 1.5m while moving 16m horizantaly
i tried everything all i figerd out is that they r displacmednts the accelaration is 9.8 and nothing i don't have enogh info to do anything

Homework Helper
Divide the motion into x and y components and deal with them as if you were dealing with one-dimensional motion.

ouse

ouse
and any way that doesn't work becuse i have no angles to detrime wat the x and y components are

ouse
that would only work if these were vectors not displacment

Homework Helper
Well...
$$x = v_0t$$
$$0 = y_0 -\frac{1}{2}gt^2$$
Does that help at all?

ouse
yeah it helped i acctualy figerd the question thanks sooo much

ouse

Homework Helper
ouse said:
yeah it helped i acctualy figerd the question thanks sooo much

Did you understand where the equations I gave came from?

ouse
ummm well yeah for one of them

ouse
u assumed viy is 0 and took it our of the equation right

Homework Helper
The full equations:
$$x = x_0 + v_{x0}t + \frac{1}{2}a_xt^2$$
$$y = y_0 + v_{y0}t + \frac{1}{2}a_yt^2$$
Let $x_0 = 0$. As the projectile's fired horizontally: $v_{y0} = 0$ thus $v_{x0} = v_0$. No force affects the projectile in x-direction, so: $a_x = 0$. In y-direction: $a_y = -g$ (- as it's downward). The final altitude of the projectile is $y = 0$.

Hence
$$x = v_0t$$
$$0 = y_0 -\frac{1}{2}gt^2$$

ouse
i was woundring if u could help me with the other thread please help me i really need it i have a test i need to pass

ouse
thx for the explination