A car slams on its brakes, coming to a complete stop in 4.0 sec. The car was traveling north at 60.0 mph. Calculate the acceleration.
To calculate the acceleration of the car, we need to use the formula:
acceleration = (final velocity - initial velocity) / time
First, let's convert the initial velocity from mph to m/s. We know that 1 mph is equal to 0.447 m/s. So, the initial velocity can be calculated as:
initial velocity = 60.0 mph * 0.447 m/s = 26.8 m/s
The final velocity is 0 m/s because the car comes to a complete stop.
The time is given as 4.0 seconds.
Now, we can substitute the values into the formula to calculate the acceleration:
acceleration = (0 m/s - 26.8 m/s) / 4.0 s
Simplifying the equation, we have:
acceleration = -26.8 m/s / 4.0 s
The negative sign indicates that the car is decelerating or slowing down.
Using simple division, we can find the acceleration:
acceleration = -6.7 m/s²
Therefore, the acceleration of the car is -6.7 m/s² (meters per second squared).