{a} {h} {c} {i} {ii} Explain whjtr a particle moving with constant speed along a circular path has an acceleration. [2 marl-ts] Ihe value of radial acceleration is given by the expression idt'i'. where 1' is the speed and r' is the radius ofthe path. Using base Lmits. show that this expression is dimensionally correct. [2 mini-ts] A racing car ofniass 500 kg starts from rest and accelerates at til} at s4 along a straight horizontal road for a distance of 131} m. It then enters. at constant speed, a horizontal circular curve of radius 20:] n1. What is the magnilude and direction of the resultant horizontal force acting on'the racing car while it is travelling around the curve? [-I marks] A stone of mass 504} g is attached to a string of length 50 cm which will break ifthe tension ezoeeds 2U N. The stone is whirled in a vertical circle. The angidar speed is slowly inereased until the string breaks. {1} (ii) {iii} Draw a diagram to show the forces acting on the stone in a vertical circle when it is at its a} highest point [1 mark b} lowest point. [1 mark} In what position along the Tsertiical circular path is the string MOST liker to break'.' Suggest a reason for your answer. [1 marks] At what angular speed will the spring break'.'I [.l'r marks]