High School Problem of the Month: January 2012
A car traveling at 40 m/s (144 km/h) passes a police car hidden behind a billboard. Two seconds after the car passes the billboard the police car is on the road accelerating at 3.0 m/s squared. How long will it take the police to catch the speeder?
Answer:
t0 = 2s for speeder ds = 40 m/s to + 40 m/s t dp = 3.0 m/s2 (t)2 ds = dp 40 (2) + 40t = 3.0t2 3.0t2 - 40t - 80 = 0 t = 40 +/- (1600 + 4(3)(80))1/2 = 15.1, -1.77 time always (t) It will take the police 15.1 s to catch the speeder.
(When you think you have the correct answer, send an email to Problem Solution (fredyouberg@nmmesa.org) with your answer. You MUST show your work! Please make the subject line of your email "Problem of the Month" and include your name, grade and school name in your email. The date and time of your email will be used to determine the order in which answers are received. The first, current MESA high school student that submits the correct answer will be the featured high school MESA student for the month. A student may be recognized only once per school year.)
