(Total 7 mar A lighthouse L is located offshore, 500 metres from the nearest point P on a long straight shoreline. The narrow beam of light from the lighthouse rotates at a constant rate of 8x radians per minute, producing an illuminated spot S that moves along the shoreline. You may assume that the height of the lighthouse can be ignored and that the beam of light lies in the horizontal plane defined by sea level. L shoreline S When S is 2000 metres from P, (a) show that the speed of S, correct to three significant figures, is 214 000 metres per minute