Victory for the ACT Student Text 15e

S CIENCE R EVIEW • 355

55. In Figure 1, the successive peaks of the diagram represent overpressure readings that are separated by: A. time only. B. distance only. C. both time and distance. D. neither time nor distance. 56. According to Figure 2, conditions during the time lag between the explosion and the arrival of the blast front are characterized by: F. negative overpressure. G. positive overpressure. H. atmospheric pressure. J. positive dynamic pressure. 57. According to Figure 2, the negative phase of the dynamic pressure is characterized by: A. positive overpressure. B. negative dynamic pressure. C. atmospheric pressure. D. variable winds. 58. According to the data provided in Figure 3, ”‡ϐŽ‡…–‡† ’”‡••—”‡ǣ F. is less than peak overpressure only for peak overpressure values between 1 and 10 PSI. G. is less than peak overpressure for all peak overpressure values between 1 and 100 PSI. H. is greater than peak overpressure only for peak overpressure values between 10 and 100 PSI. J. is greater than peak overpressure for all peak overpressure values between 1 and 100 PSI.

According to the data provided in Figure 3, the difference in the velocity of a shock wave for a peak overpressure of 1 PSI and the velocity of a shock wave for a peak overpressure of 100 PSI is approximately: A. 18 feet per second. B. 180 feet per second. C. 1,800 feet per second. D. 18,000 feet per second.

59.