Time, Speed, and Distance


  1. Distance = Speed × Time

  2. Speed =
       Distance
    Time


  3. Time =
       Distance
    Speed


  4. 1 km/hr =
       5
    18
    m/s       
    1 m/s =
       18
    5
    km/h

  5. Average Speed =
       Total Distance
    Total Time


  6. When half distance is covered with speed of x km/h and other half with y km/h, then
          Average Speed =
       2xy
    x + y


  7. When equal distances are covered with speed of x km/h, y km/h, and z km/h, then
          Average Speed =
       3xyz
    xy + yz + zx


  8. When two bodies are moving in same direction with speed of x km/h and y km/h, then their
          Relative Speed = (x - y) km/h,     if x > y       Relative Speed = (y - x) km/h,     if x < y

  9. When two bodies are moving in opposite direction with speed of x km/h and y km/h, then their
          Relative Speed = (x + y) km/h


  10. Boats and Streams:
    If A is speed of current,
    B is speed of Boat,
    U is downstream speed of boat, and
    V is upstream speed of boat, then




  11. Circular Motion: