A car moves with a speed of 80 m/s. If the driver used the brakes to decrease the speed, so it decreases by 2 m/sec^2. What is its speed after 12 seconds from using the brakes?
Here you can use the cinematic relationship:
in your case:
The car's speed after twelve seconds of using brakes is
If the car's acceleration due to braking is
Therefore, if the car's speed is