Question

A car is going 10m/s before you press on the

breaks. If it has an acceleration of -5 m/s²
How far did the car travel after the brakes were pressed?
A) 10 meters
B) 20 meters
C) 5 meters
D) 15 meters

Answer 1

The car traveled a distance of 10 meters after the brakes were pressed. This is determined by rearranging and solving the kinematic equation for final velocity set to zero with the given initial velocity and negative acceleration.

Step-by-step explanation:

To find out how far the car traveled after the brakes were pressed, we can use the formula for the distance traveled under constant acceleration (deceleration in this case):

d = ½ at² + v0t + d0

Here, a is the acceleration, t is the time, v0 is the initial velocity, and d0 is the initial position. Since we don't have the time it took the car to stop, we'll use the formula for the final velocity:

v² = v0² + 2ad

Given the car stops (final velocity v = 0), the initial velocity v0 = 10 m/s, and the acceleration a = -5 m/s², we can solve for d (distance after the brakes are pressed).

0 = (10 m/s)² + 2(-5 m/s²)d

0 = 100 m²/s² - 10d

d = 100 m²/s² / 10 = 10 meters

The correct answer is A) 10 meters.