9709 P12 - Nov 2018 - Q7
2263
The diagram shows a solid cylinder standing on a horizontal circular base with centre O and radius 4 units. Points A, B and C lie on the circumference of the base such that AB is a diameter and angle BOC = 90^ ext{o}. Points P, Q and R lie on the upper surface of the cylinder vertically above A, B and C respectively. The height of the cylinder is 12 units. The mid-point of CR is M and N lies on BQ with BN = 4 units.
Unit vectors i and j are parallel to OB and OC respectively and the unit vector k is vertically upwards.
Evaluate \(\overrightarrow{PN} \cdot \overrightarrow{PM}\) and hence find angle MPN.
