Speed, distance & time - Wiki

  • #speeddistance
    • 40 students lined up in a row along the corridor with an equal spacing of 2 m apart to welcome the Guest-of-Honour (GOH) at a school event. The GOH then walked along the row to shake each student's hand. (a) Starting from the first student, how far would the GOH have walked when he shook the `10^(th)` student's hand? (b) When the GOH had walked a total of 58 m, how many students' hands would he have shaken? Ans: (a) _BLANK_ [1] Ans: (b) _BLANK_ [2]
      • #speeddistance&time

        The no. 2 m space from the first to the 10th student = 9

        Distance the GOH have walked at the 10th student

        `xx` 2 = 18 m

        (part b)

        No. of spacing the GOH have walked across

        58 `-:` 2 = 29

        No. of student hands the GOH have shaken

        29 + 1 = 30  

    • Peter and John started running in opposite directions from a same spot. After 36 minutes, the distance between the 2 boys was 7920 m. (a) Given that Peter ran 3 times as fast as John, find Peter's speed. Give your answer in m/min. (b) How long would they have to run to be 12 760 m apart? Give your answer in minutes Ans: (a) _BLANK_ m/min [2] Ans: (b) _BLANK_ m [2]
      • #speeddistance&time

        (part a):

        P : J

        3 : 1

        Toatal = 3u + !u = 4u

        4u = 7920 m

        1u = 1980 m

        Peter's distance ran

        3u = 1980 `xx` 3 = 5940 m

        Peter's speed

        5940 `-:` 36 = 165 m/min

        (part b):

        To be 12760 m apart, Peter has to cover

        12760 `xx` `3/4`  = 9570m

        Time Peter takes to travel 9570 m

        9570 `-:` 165 = 58 m