Technical Drawing - Exam Papers - Higher - 1996 - Paper 1

Question 5

Fig. 4 shows a circle and one convolution of a logarithmic spiral. The spiral has an initial radius of 45mm and the lengths of succeeding radii decrease in the ratio of 8 : 9 over successive 30° intervals.

(a) Draw the given circle and logarithmic spiral.

(b) The circle rolls along the line AB for one complete revolution. During the rolling of the circle the point P moves along the straight line to C.

Draw the locus of the point P for the combined movement.