6 (B420U10-1) Examiner only 3. When colliding two protons at very high energy the following interaction has been observed at the large hadron collider in CERN. p + p → H + e+ + x (a) Use the conservation of lepton number and conservation of charge to identify the particle x. [3] (b) State which force is responsible for this interaction. Give your reasoning. [2] (c) State which of the above particles can be classed as: [2] (i) a baryon; (ii) an antiparticle. (d) At present, countries in Europe contribute to funding research at CERN. Evaluate whether or not the money could be better spent on humanitarian aid. [2] © WJEC CBAC Ltd. 2 1 9 (B420U10-1) Turn over. B 420 U101 07 7 Examiner only 4. In this question the Sun and the star Vega can be considered to be black bodies. (a) (i) Define a black body. [1] (ii) The surface temperature of the Sun is approximately 6 000 K and that of Vega approximately 10 000 K. Calculate the wavelength of peak spectral intensity for each star and name the region of the electromagnetic spectrum within which they lie. [3] (iii) Sketch a black body spectrum for each star on the axis provided. [3] © WJEC CBAC Ltd. Spectral intensity Wavelength 8 (B420U10-1) Examiner only (b) The radius of Vega is approximately 2.71 times that of the Sun. Determine the ratio: [4] © WJEC CBAC Ltd. total power output of Vega total power output of Sun 11 BLANK PAGE 9 © WJEC CBAC Ltd. (B420U10-1) Turn over.