Please help me with this Calculus questions

Question 4 (a) A particle moves along the curve y =4xV2x -7 in such a way that the x- coordinate of the particle is increasing at a constant rate of 0.5 units per second. Find the rate of the y - coordinate of the particle at the instant when x =4. ( 5 marks ) (b) The diagram below shows an inverted right circular cone with base radius 12 cm and height 30 cm. Initially, it is filled with water. Water leaks through a small hole at the vertex P at the rate of 4 cm3/min. 12 cm 30 cm h (i) Express r in terms of h. ( 3 marks ) (ii) Show that the volume of water in the cone, V cm3, in terms of height, h, is given by V 47th ( 3 marks ) 75 (iii) Find the rate of change of the depth of the water when h =5 cm. What does the answer imply? ( 4 marks )