A circular wheel is used in a laboratory experiment to measure distance travelled along a straight line.
a. (i) Write the formula for the circumference C of a circle of radius r.
b. (ii) Give a brief reason, in one or two sentences, why multiplying the circumference of the wheel by the number of its complete revolutions gives the linear distance covered by a point on its rim.
c. (iii) The wheel has radius 14cm and makes 250 complete revolutions. Calculate, correct to the nearest metre, the distance travelled by the point on its rim.