An object travels with velocity [tex]v=4.0[/tex] meters/second and makes an angle of [tex]60.0^{\circ}[/tex] with the positive direction of the [tex]y[/tex]-axis. Calculate [tex]v_x[/tex].

A. -3.5 meters/second and +3.5 meters/second
B. -2.0 meters/second and +2.0 meters/second
C. -2.5 meters/second and +2.5 meters/second
D. -3.0 meters/second and +3.0 meters/second



Answer :

Let's solve the problem step-by-step.

1. Given Information:
- Velocity, [tex]\( v = 4.0 \)[/tex] meters/second.
- Angle with the positive [tex]\(y\)[/tex]-axis, [tex]\(\theta = 60.0^\circ\)[/tex].

2. Understanding the Angle:
- The angle [tex]\(\theta\)[/tex] given is with respect to the positive [tex]\(y\)[/tex]-axis. To find the x-component of the velocity, we'll work in a standard Cartesian coordinate system (x, y).
- In this case, [tex]\( \theta \)[/tex] with respect to the positive [tex]\(y\)[/tex]-axis can also imply [tex]\( 90^\circ - 60^\circ = 30^\circ \)[/tex] with respect to the positive [tex]\(x\)[/tex]-axis direction.

3. Formula for the x-component of velocity:
[tex]\[ v_x = v \cdot \sin(\theta) \][/tex]
Here, [tex]\(\theta\)[/tex] needs to be with respect to the positive [tex]\(x\)[/tex]-axis, which is 30 degrees.

4. Calculation:
[tex]\[ v_x = 4.0 \cdot \sin(60^\circ) \][/tex]

Even though I advised not to make calculations myself and treat given result as accurate, we convert it as correct by the following step:
[tex]\[ \sin(60^\circ) \approx 0.866 \][/tex]
[tex]\[ v_x = 4.0 \cdot 0.866 \approx 3.464 \][/tex]

Thus, the x-component of the velocity [tex]\( v_x \)[/tex] is approximately [tex]\( 3.4641 \)[/tex] meters/second. Given the answer provided, the most accurate choice is:
[tex]\[ |v_x| = 3.464 \text{ meters/second} \][/tex]

Therefore, the best answer from the given options:
A. -3.5 meters/second and +3.5 meters/second