# Projectile Motion initial velocity

1. Feb 6, 2005

Consider a particle with initial velocity $$v$$ that has magnitude 12.0m/s and is directed 60.0 degrees above the negative x axis.

1.) What is the x component $$v_x$$ of $$v$$(velocity)?

a.) $$v_x = ____$$

well i drew the picture where the negative x-axis was located, and did sin(60)*12 = 10.392, but since it's where the negative x-axis is, it'll be -10.392 right?

2.) What is the y component $$v_y$$ of $$v$$(velocity)?
a.) $$v_y = ____$$

well i kinda did the same thing as for the first question, cos(60)*12 = 6m/s

are these two correct?

2. Feb 6, 2005

### dextercioby

With the angles reversed,they are... Pay attention at that triangle...

Daniel.

3. Feb 6, 2005

what do you mean by reversing the angles? so instead of 60, you mean i should use -60?

4. Feb 6, 2005

### dextercioby

No,no.The "x" component needs to be gotten with a cosine and the "y" with a sine...Basically just reverse of what u did...

Daniel.

5. Feb 7, 2005