Tuesday, 11 December 2007

Q7 - Circles & circumferences

7
a) 'Pi' the weasel (Yes that is a hint) likes to play in a wheel with a diameter of 15cm. What is the circumference of the wheel? (Give your answer to 2 significant figures)
b) Another wheel they like has a circumference of 40cm. If the wheel rolled for 30 metres, how many times would it have turned?
(4 marks)
a) Circumf = 15 x 3.14 = 47.1.. = 47 cm (2sf)
b) 3000 / 40 = 75 times

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