Savchenko Problem 1.2.16
Physics · mechanics
Problem
The graphs of the coordinate dependence on time plotted in different time scales for two particles turned out to be the same. One division of the time axis t for the graph of the first particle corresponds to 4 s, and for the graph of the second—1 s. Find the ratio of velocities and the ratio of particle accelerations for point A of the graph.Intuitive explanation
The key insight is that identical graph shapes with different time scales reveal how velocity and acceleration scale with time. Since both particles trace the same curve on their respective graphs, their position functions have the same mathematical form—but time is compressed or stretched by a factor of 4 between them. When you change the time scale, velocities scale inversely with time (faster clock = steeper slope per unit real time), while accelerations scale as the inverse square of the time scale. Use the chain rule: if particle 1's time axis is stretched 4× relative to particle 2's, then and .
Intuitive explanation
The key insight is that identical graph shapes with different time scales reveal how velocity and acceleration scale with time. Since both particles trace the same curve on their respective graphs, their position functions have the same mathematical form—but time is compressed or stretched by a factor of 4 between them. When you change the time scale, velocities scale inversely with time (faster clock = steeper slope per unit real time), while accelerations scale as the inverse square of the time scale. Use the chain rule: if particle 1's time axis is stretched 4× relative to particle 2's, then and .