Homework Help: Projectile Motion initial velocity

1. Feb 6, 2005

ProBasket

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)?

Express your answer in meters per second.

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

ProBasket

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

ProBasket

ah thanks for the help, i had my triangle label incorrectly by mistake

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