Question

A car is moving at 14.4 m/s when it hits the brakes. It slows for 78.8 m, taking 9.92 s. What is the car's acceleration during the braking period? a) 2.38 m/s² b) 3.17 m/s² c) 4.02 m/s² d) 5.11 m/s²

Answer 1

A car is moving at 14.4 m/s when it hits the brakes. It slows for 78.8 m, taking 9.92 s, the car's acceleration during the braking period is -1.45 m/s² (the correct answer is not listed among the options provided).

Step-by-step explanation:

To calculate the car's acceleration during the braking period, we can use the equation:

acceleration = (final velocity - initial velocity) / time

In this case, the initial velocity is 14.4 m/s and the final velocity is 0 m/s (since the car comes to a stop).

The time it takes to slow down is 9.92 s. Plugging these values into the equation gives:

acceleration = (0 m/s - 14.4 m/s) / 9.92 s = -14.4 m/s / 9.92 s = -1.45 m/s²

Since acceleration is a vector quantity, the negative sign indicates that the car is decelerating, or slowing down. So, the correct answer is not listed among the options provided.