return shift P.8 of 9 Part D: Application (12 marks) 1. The magnitude (M) of an earthquake on the Richter scale is given by log E=1.5 M + K where E is the energy released as seismic waves (in Joules) from the earthquake and K is a constant. (a) The energy released as seismic waves in the earthquake in city A in 1991 and 2008 were 7.53X10 Joules and 3.68X10" Joules respectively. Find the difference in magnitudes of the two earthquakes on the Richter scale. (Give your answer to 2 decimal places.) (4 marks) ( b) How many times is the energy released as seismic waves in an earthquake measured 7 on the Richter scale to that measured 4 on the Richter scale? (Give your answer to 2 decimal places.) (5 marksP.5 of 9 2. A radioactive substance has a half-life of 7 hours. P.9 of 9 after t = 21 hours . If a sample of the substance has an initial mass of 2000g, what is the mass of the substance The fi (3 marks) Whic A. C1 B. C2 C. C D. Bonus (3 marks) It is given that x+x =5 . Without solving for x, what is the value of x2+x-2 ? 9. A ~ ~ ~ End of Test 3 ~ ~ ~