What is the rate of deceleration of a 1400-kg SUV that is going 75.0 km/h and then slows to 25.0 km/h in 8.20 s?
To determine the rate of deceleration, we need to use the equation for acceleration:
acceleration = (final velocity - initial velocity) / time
First, let's convert the velocities from km/h to m/s.
Given:
- Initial velocity (v1) = 75.0 km/h
- Final velocity (v2) = 25.0 km/h
- Time (t) = 8.20 s
Converting the velocities:
- Initial velocity (v1) = 75.0 km/h * (1,000 m/1 km) * (1 h/3600 s) = 20.8 m/s
- Final velocity (v2) = 25.0 km/h * (1,000 m/1 km) * (1 h/3600 s) = 6.94 m/s
Now we can calculate the acceleration:
acceleration = (v2 - v1) / t
= (6.94 m/s - 20.8 m/s) / 8.20 s
Simplifying the equation:
acceleration = -13.86 m/s / 8.20 s
Therefore, the rate of deceleration of the SUV is approximately -1.69 m/s².