Internet Scavenger Hunt Name ________________________ Click on the following Internet sites to answer the questions for that site: http://www.adtdl.army.mil/cgi-bin/atdl.dll/fm/5-233/Ch3.htm 1. Label the four types of curves below: a. (simple) b. (compound) c. (reverse) d. (spiral) 2. Review the video of the I-35 to I-10 interchange on the first page of the module site. Decide the type of curve the I-35 to I-10 interchange fits. (reverse) 3. Which type of curve is most commonly used? (simple) 4. Which type of curve, for safety reasons, should be used only when absolutely necessary? (reverse) http://oldsci.eiu.edu/physics/DDavis/1150/05UCMGrav/Curve.html 5. What does the net force on a car traveling around a curve equal? ( centripetal force) 6. What is the direction of the centripetal force? (inward) 7. What supplies the centripetal force for a car on a level curve? (frictional force between the road and tires) 8. What is the direction of the frictional force for a car traveling on a curve? (inward) 9. What type of frictional force - static or kinetic - is used to determine the coefficient of friction between the tire of the car and the road? (Static friction) 10. What equation gives the angle necessary for a car traveling at a specified speed on a banked curve? (tan q = v^2/gr) http://www.tfhrc.gov/pubrds/pr97-10/p47.htm 11. What is meant by the term design frequency? (refers to a roadway's design conformance with driver expectancy) 12. Define the term roadway design speed?( the maximum speed at which a driver can operate uniformly through all the geometric features of the roadway without deviation from assumed design criteria) 13. What relationship was found between the required speed reduction and the likelihood drivers will not reduce their speed as much as required? (the higher the required speed reduction the higher the likelihood drivers will not reduce their speed the required amount) 14. Click on figure 2 to answer the following question. How many times greater would the expected crash rate of a curve with a speed reduction of 20 km/h be than the crash rate on a curve that requires no speed reduction.(6 times) http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/circmot/ucm.html 15. Define uniform circular motion. (the motion of an object in a circle at a constant speed) 16. What is the direction of the velocity vector relative to the circle? (tangent to the circle) 17. What two vector forces are perpendicular to each other in the diagram? (ac and v) 18. An object moving in a circle at constant speed is undergoing uniform circular motion. Why is the velocity changing? (although the speed is constant the direction is always changing) http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/circmot/cf.html 19. What is the direction of the net force and what does it equal? ( inward, centripetal force) 20. Which of Newton's Three Laws of Motion is used to explain why the ball in the second animation travels in a curved path? (2nd Law) http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/circmot/rht.html 21. View the animation. What supplies the force to make the passenger travel around the corner? ( the driver) http://phywwwl.ncssm.edu/edtech/physlets/CURVE/curveframe.htm 22. What are the two components of the normal force on banked curves? (Fnsinq, Fncosq) 23. Give an equation that shows the summation of the forces in the y-direction.( ? Fy = Fncos? - Fg = 0) 24. Give the equation for centripetal force. (Fc = Fnsin? = mv^2/r) 25. When you increase the banking angle, how can the maximum safe speed change? ( it can become greater) 26. What is another name for the resultant of all forces? (net force) 27. Where does the net force acting toward the center of the curve come from? (Static friction) 28. On unbanked curves, the centripetal force is equal to what expression? (Fc = µsFn = µsmg = mv^2/r) 29. Which of the following variables - mass, speed, radius, gravity, static friction - is not needed to calculate the centripetal acceleration? (mass) http://oldsci.eiu.edu/physics/DDavis/1150/05UCMGrav/UCM.html 30. What is the symbol for angular velocity and what is its unit? (w, radians/second) 31. Give the formula to convert angular speed to linear speed. (v = rw) http://www.pen.k12.va.us/Anthology/Pav/Science/Physics/book/curve.f/curves.html 32. Which way will a car tip if there is too much bank for a car's velocity? ( to the inside) 33. Which way will a car tip if there is not enough bank for a car's velocity? ( to the outside)