HW#3 Ch 2: Motion Along a Straight Line
Instructions: Answers must start with a formula to receive credit.
1. a) An electron travels a distance of 1.83 m (6 ft) in a vacuum at an average speed of 4.00 x 107 m/s. How long does the trip take in nanoseconds? b) The same electron travels at an average speed of 4.00 x 10−5 m/s through a 6ft. extension cord. How long does it take to travel this distance in hours? (The electron travels more slowly through a wire due to the numerous collisions with other electrons.)
2. A jogger travels 5.0 km in 20 min and then takes 60 min to walk back to the starting point. a) What is the jogger’s average velocity for the first 20 min? b) What is the average velocity for the time spent walking? c) What is the average velocity for the whole trip? d) What is the average speed for the whole trip? All answers must be in m/s.
3. A car heads east with an average velocity of 60. km/h for 3.5 h and then west with an average velocity of 30. km/h for 1.5 h. a) What is the total displacement for the 5 h trip, in kilometers? b) What is the average velocity for the total trip, in kilometers per hour?
4. Greg LeMond owns the record for the fastest individual time trial at the Tour de France, with an average speed of 54.545 km/h. If riders are released every 2 minutes, in how many kilometers will LeMond overtake the previous rider, if the previous rider has an average speed of 50.777 km/h?