# If she hits the brakes, how far will she travel before stopping?

#### rakesh44

1. Homework Statement
A person driving her car at 56 km/h approaches an intersection just as the traffic light turns yellow. She knows that the yellow light lasts only 2.0 s before turning to red, and she is 30 m away from the near side of the intersection (Fig. 2-29). Should she try to stop, or should she make a run for it? The intersection is 15 m wide. Her car's maximum deceleration is -5.6 m/s2, whereas it can accelerate from 56 km/h to 70 km/h in 4.2 s. Ignore the length of her car and her reaction time. If she hits the brakes, how far will she travel before stopping?

2. Homework Equations
can someone at least give me a formula that i can use to find the answer??
thankss

Related Introductory Physics Homework Help News on Phys.org

#### rl.bhat

Homework Helper
Refer any text book and list the kinematic equations.

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving