Chasing a Car: The 20-Meter Warning Window
This animation visualizes a classic kinematics problem: a car accelerates from rest at 1 m/s² while a person 60 m behind chases at constant speed, needing to stay within 20 m of the car for at least 2 seconds to shout a warning. A marker point 20 m behind the car tracks the changing gap as the person closes in, passes the point, then falls behind, paired with a synchronized v-t graph. Useful for students learning relative motion, closing speed, and how to translate a word problem into graphical reasoning.
16:9 · Preview before teaching · automatic layout checks do not establish subject accuracy
The prompt that made it
汽车以 1 m/s2的加速度启动，同时车后 60 m 远处有一人以一定的速度 v0匀速追赶要车停下.已知在人离车的距离小于 20 m、持续时间为 2 s 喊停车才能把信息传给司机。在车后20米挂一个点，生成人追车超过点以及点追人的动态图以及v-t图像，人超过车后20米点和点追人的距离拉长、速度放缓，在视觉上足够明显，过程足够清晰，不必严格按照现实比例尺，目的在于让过程清晰，让学生一目了然
Make the next one in this series
- Solve algebraically for the range of v0 that satisfies the 2-second shouting condition
- Compare three different v0 values side by side to show success versus failure cases
- Animate a similar pursuit problem with a person boarding a departing train
