Question

A projectile is fired with a velocity of 150 meters per second at an angle of 30 degrees above the horizontal. Calculate the magnitude of the horizontal component of the velocity at the time the projectile is fired.

(A) 130 m/s
(B) 129.9 m/s
(C) 75 m/s
(D) 150 m/s

Answer 1

The horizontal component of the velocity for a projectile fired at 150 m/s at a 30-degree angle above the horizontal is 129.9 m/s, found using the cosine function of the angle.

Step-by-step explanation:

The question asks to calculate the magnitude of the horizontal component of the velocity for a projectile fired at an angle above the horizontal plane. In physics, specifically projectile motion, the velocity of a projectile can be decomposed into horizontal (vx) and vertical (vy) components using trigonometric functions, given the initial velocity (v) and the angle of launch (θ).

Given:
Initial velocity (v) = 150 m/s
Launch angle (θ) = 30°

To find the horizontal component (vx), we use the cosine function:

vx = v * cos(θ)

vx = 150 m/s * cos(30°)

vx = 150 m/s * (√3/2)

vx = 150 m/s * 0.866

vx = 129.9 m/s

Therefore, the horizontal component of the velocity when the projectile is fired is 129.9 m/s, which corresponds to option (B).