Braking Problem: An Amtrak train bound from New York City to Savannah, Georgia derailed south of Philadelphia on 3rd April, 2016. According to the news article, it was going at 106mph (the speed limit on this section of track is 110mph) when the engineer saw a backhoe on the track and put the train into emergency braking with about 5 seconds to go. The impact derailed the lead engine of the train Reuters v = vo + at Svotat Equations used in Constant Velocity svt, i.e. a 0 Equations used in Constant Acceleration Where: s = distance v = velocity Vo initial velocity a = acceleration (v +10) S= -t 5,280 ft 1 mile 2 mph x 22/15 ft/sec v = v + 2as Use consistent units! Force and Acceleration, Friction F = ma Fr = UN m = W/g Where m is mass and g is acceleration due to gravity. Use: g = 32.2ft/sec Fr is the maximum available friction force u is the coefficient of Friction N is the Normal force, in this case W At this deceleration, how fast was the train going at impact (in ft/sec and mph)? At this deceleration, what distance would have been needed to avoid collision? How much time would this be? Use a different equation to check your values of a, s & t