Answer Happy

21. The speed of sound in steel is 5000 m/s. What is the wavelength of a sound wave of frequency 660 Hin steel? A) 7.58 m B) 2.41 m C) 1.21 m D) 0.829 m E) 0.132 m Questions 22-23 refer to the diagram shown at right. 22. The wavelength is.... A 2 cm. B. 3 cm. C. 4 cm. D. 5 cm. y(mm) 2 3 4 23. The amplitude is... A. Flem B. C. D. 24. A radar operates at a wavelength of 3 cm. What is the frequency of its waves? The speed of a radio wave is 3.0x10m/s A. 10-10 Hz B. 106 Hz C. 10 Hz D. 1000 Hz 3 m. 30 cm. 3 mm 60 cm. Electrostatics 25. The reason a pith ball will be attracted to a charged rubber rod is that... A) the rod is positive and attracts electrons in the pith ball. B) the rod is negative and repels electrons in the pith ball, attracting the nearer protons. C) the rod is positive and repels electrons in the pith ball, attracting the nearer protons. D) the rod is negative and attracts electrons in the pith ball. 26. Which diagram represents a possible electric field surrounding two unlike charges? b) c) a)