North Carolina RADAR State Practice Exam

At 80 MPH, how long is the reaction time distance?

1. 44 ft

2. 88 ft

3. 66 ft

4. 104 ft

The correct answer is: 88 ft

To determine the reaction time distance at 80 MPH, it's essential to understand how the speed of a vehicle affects the distance traveled during a driver's reaction time when they perceive a need to stop. Reaction time distance can be calculated using the formula: **Reaction Distance (feet) = Speed (MPH) × Reaction Time (seconds) × 1.47** Assuming a typical reaction time of about 1.5 seconds, the calculations would be as follows: 1. Convert the speed into how far the vehicle travels in one second: - At 80 MPH, the vehicle travels approximately \( 80 \times \frac{5280 \text{ feet}}{3600 \text{ seconds}} \), which simplifies to about 117.33 feet per second. 2. Multiply by the reaction time (let's assume 1.5 seconds as average): - \( 117.33 \text{ feet/second} \times 1.5 \text{ seconds} = 176 \text{ feet} \). However, this doesn't produce any of the given choices, so we'll use an approximate reaction distance formula based on typical driving scenarios or simplified calculations commonly used in driver's ed courses that estimates reaction distance in general terms