Question

A cannonball is launched with an initial horizontal velocity of 45 m/s, west, and an initial vertical velocity of 5 m/s, up. Assuming projectile motion, what will be the magnitude of the cannonball's horizontal velocity at three seconds?

A) 0 m/s
B) 45 m/s
C) 15 m/s
D) 30 m/s

Answer 1

Option B) 45 m/s is correct because the horizontal velocity of a projectile remains constant in projectile motion unless there's horizontal acceleration, which is not present in this scenario.

Step-by-step explanation:

The question is concerned with understanding the properties of projectile motion in Physics, specifically relating to the horizontal component of velocity of a cannonball after it has been fired. In the absence of air resistance, the horizontal velocity of a projectile remains constant because there is no horizontal acceleration acting on it. Therefore, since the cannonball was launched with an initial horizontal velocity of 45 m/s west, the magnitude of the cannonball's horizontal velocity at three seconds will still be 45 m/s.

Option B) 45 m/s is the correct answer to the question of what the magnitude of the cannonball's horizontal velocity will be at three seconds after it has been fired.