A car moving with a speed of 12 m/s is subjected to brakes which produces a deceleration of 6 m/s². The car takes 2 s to stop after the application of brakes. What is the distance covered by the car after the application of brakes?

To find the distance covered by the car after applying brakes, we use the kinematic equation for uniformly accelerated motion: s = ut + (1/2)at² [1]. Given the initial velocity (u) is 12 m/s, the time (t) is 2 s, and the deceleration (a) is 6 m/s² (which is expressed as -6 m/s² in the formula because it acts opposite to the motion). Substituting these values: s = (12 × 2) + (1/2 × -6 × 2²). This simplifies to s = 24 + (1/2 × -6 × 4), which is s = 24 - 12 = 12 m. Alternatively, using the formula v² = u² + 2as where final velocity (v) is 0, we get 0 = 12² + 2(-6)s, leading to 144 = 12s, which also results in s = 12 m. Thus, the car covers 12 meters before coming to a complete stop.

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 8: Measurement of Time and Motion > 8.3 Speed > p. 113