Question

An object that is launched from the top of the tower is dense enough that air resistance can be ignored. The object's initial velocity has components (Vx = 30 m/s, Vy = 20 m/s). What are the components of the object's velocity 3 seconds after launch?

A) (vx = 0 m/s, Vy = -10 m/s)
B) (Vx = 0 m/s, Vy = 20 m/s)
C) (Vx = 30 m/s, Vy = -10 m/s)
D) (Vx = 30 m/s, Vy = 50 m/s)"

Answer 1

The object will have a horizontal velocity component of 30 m/s and a vertical component of -10 m/s after 3 seconds.

Step-by-step explanation:

The components of the object's velocity 3 seconds after launch can be calculated using the principles of projectile motion. Since air resistance is ignored, the horizontal component of velocity, Vx, remains constant throughout the motion. Therefore, after 3 seconds, Vx is still 30 m/s. The vertical component of velocity, Vy, is affected by gravity, which accelerates the object downward at 9.8 m/s2. The initial vertical component of velocity is 20 m/s upwards, so after 3 seconds, gravity would have reduced this by (9.8 m/s2 × 3 s = 29.4 m/s). The vertical component of velocity after 3 seconds is therefore 20 m/s - 29.4 m/s = -9.4 m/s (rounded to -10 m/s for simplicity). Thus, the correct answer is C) (Vx = 30 m/s, Vy = -10 m/s).