{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

CHAPTER 2 - 19

# CHAPTER 2 - 19 - (50km/h(3.6ks/h)=13.9m/s(a ,...

This preview shows pages 1–2. Sign up to view the full content.

We convert the units for the speed limit:  (50 km/h)/(3.6 ks/h) = 13.9 m/s.   ( a ) If we assume that we are traveling at the speed limit, the time to pass through the farthest  intersection is t 1  = ( d 1  +  d 2  +  d 3  +  d 4  +  d 5  +  d 6 )/ v 1  = (10 m + 15 m + 50 m + 15 m + 70 m + 15 m)/(13.9 m/s) = 12.6 s. Because this is less than the time while the lights are green,        yes ,      you can make it through. ( b ) We find the time required for the second car to reach the speed limit: v max  =  v 02   +   a 2 t 2a ; 13.9 m/s = 0 + (2.0 m/s 2 ) t 2a   , which gives  t 2a  = 6.95 s. In this time the second car will have traveled x 2a  =  v 02 t 1  +  ! a 2 t 2a 2  = 0 +  ! (2.0 m/s 2 )(6.95 s) 2  = 48 m. The time to travel the remaining distance at constant speed is t 2b   = ( d 2  +  d 3  +  d 4  +  d 5  +  d 6  –  x 2a )/ v max   = (15 m + 50 m + 15 m + 70 m + 15 m – 48 m)/(13.9 m/s) = 8.42 s.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern