Final Answer:
In the context of an airplane traveling at a constant speed of 180 km/h, it implies that there is no net force acting on the airplane in the horizontal direction.
The correct answer is B) Experiences constant speed.
Step-by-step explanation:
In the context of an airplane traveling at a constant speed of 180 km/h, it implies that there is no net force acting on the airplane in the horizontal direction. According to Newton's first law of motion, an object will remain at rest or move at a constant velocity unless acted upon by a net external force. In this case, the absence of acceleration or deceleration suggests that the forces acting on the airplane, such as thrust and air resistance, are balanced, resulting in a constant speed.
When an airplane is in level flight with a constant velocity, the forces acting on it are in equilibrium. The thrust produced by the engines propels the airplane forward, while the drag force exerted by the air resistance opposes this motion. These forces are balanced, leading to a constant horizontal velocity. If the airplane were to accelerate or decelerate, there would be an unbalanced force, but the question specifies a constant speed of 180 km/h, indicating a state of dynamic equilibrium.
To further illustrate, consider the forces involved. If \( F_{\text{thrust}} \) represents the forward thrust and \( F_{\text{drag}} \) represents the backward drag force, the equation for equilibrium is \( F_{\text{thrust}} = F_{\text{drag}} \). In a scenario of constant speed, these forces are equal, resulting in a net force of zero and confirming the airplane's steady horizontal motion.The correct answer is B) Experiences constant speed.