Question

in a movie, a car drives forward off a cliff, crashing into the ocean. which describes its velocity while it is in the air correctly? assume there is no air resistance. (1 point) the horizontal and vertical velocities remain constant. the horizontal velocity changes, and the vertical velocity remains constant. the horizontal and vertical velocities both change. the horizontal velocity remains constant, and the vertical velocity changes.

Explanation:

Step1: Analyze horizontal motion

In the absence of air - resistance, there is no horizontal force acting on the car. According to Newton's first law, an object in motion will stay in motion with a constant velocity if no net force acts on it. So the horizontal velocity $v_x$ remains constant.

Step2: Analyze vertical motion

The car is in free - fall in the vertical direction. There is a gravitational force $F = mg$ acting on it, where $g$ is the acceleration due to gravity. According to Newton's second law $F=ma$, the car has a vertical acceleration $a = g$. Since $a=\frac{\Delta v_y}{\Delta t}$, the vertical velocity $v_y$ changes over time.

Answer:

The horizontal velocity remains constant, and the vertical velocity changes.