Circumference and arc length

  • Track design
    problem

    Track design

    Age
    14 to 16
    Challenge level
    filled star empty star empty star

    Where should runners start the 200m race so that they have all run the same distance by the finish?

  • Over The Pole
    problem

    Over the pole

    Age
    16 to 18
    Challenge level
    filled star filled star filled star
    Two places are diametrically opposite each other on the same line of latitude. Compare the distances between them travelling along the line of latitude and travelling over the nearest pole.
  • Flight Path
    problem

    Flight path

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    Use simple trigonometry to calculate the distance along the flight path from London to Sydney.
  • Rolling Inside
    problem

    Rolling inside

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    Weekly Problem 11 - 2007
    A circle of radius 1 rolls without slipping round the inside of a square of side length 4. Find an expression for the number of revolutions the circle makes.
  • Running Race
    problem

    Running race

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    Weekly Problem 13 - 2006
    If three runners run at the same constant speed around the race tracks, in which order do they finish?
  • Roll On
    problem

    Roll on

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    Weekly Problem 5 - 2006
    How many times does the inside disc have to roll around the inside of the ring to return to its initial position?
  • Efficient cutting
    problem

    Efficient cutting

    Age
    11 to 14
    Challenge level
    filled star filled star filled star
    Use a single sheet of A4 paper and make a cylinder having the greatest possible volume. The cylinder must be closed off by a circle at each end.
  • Air Routes
    problem

    Air routes

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    Find the distance of the shortest air route at an altitude of 6000 metres between London and Cape Town given the latitudes and longitudes. A simple application of scalar products of vectors.
  • Rollin' Rollin' Rollin'
    problem

    Rollin' rollin' rollin'

    Age
    11 to 14
    Challenge level
    filled star filled star filled star
    Two circles of equal radius touch at P. One circle is fixed whilst the other moves, rolling without slipping, all the way round. How many times does the moving coin revolve before returning to P?
  • Triangles and petals
    problem

    Triangles and petals

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    An equilateral triangle rotates around regular polygons and produces an outline like a flower. What are the perimeters of the different flowers?