14. A 2.0 m string is fixed at both ends and tightened until the wave speed is 80 m/s. What is the frequency of the standing wave shown in the figure?
(A) 60 Hz
(B) 120 Hz
(C) 240 Hz
(D) 360 Hz
(E) 480 Hz

10. A particle experiences a force given by F(x) = α - βx3. Find the potential energy U(x) of the particle.(Assume that the zero of potential energy is located at x = 0.)(A) (B) (C) U(x) = 3βx2(D) U(x) = -3βx2 (E) U(x) = -6βx

11. A DC voltage of 110 V is applied to a heater whose resistance is 15 Ohms when it is hot. At whatrate is electrical energy transferred to thermal energy _____.(A) 807 W (B) 1650 W (C) 8150 W (D) 12375 W (E) 24750 W

12. A wave has an angular frequency of 110 rad/s and a wavelength of 1.8 m. Calculate the angularwave number.(A) (B) (C) (D) (E)

13. A transverse wave traveling along a string transports energy at a rate r. If we want to double thisrate, we could increase the amplitude of the wave by a factor of _____.(A) 8 (B) 4 (C) 2 (D) √2 (E) √8

15. The speed of yellow light (from a sodium lamp) in a certain liquid is measured to be 1.92 × 108m/s. What is the index of refraction of this liquid for the light?(A) 1.49 (B) 1.53 (C) 1.56 (D) 1.62 (E) 1.67

16. Which of the following statements is incorrect?(A) The emission spectrum of hydrogen contains a discontinuum of colors.(B) Diffraction produces both constructive and destructive interference.(C) All matter exhibits both particle and wavelike characteristics.(D) Niels Bohr developed a quantum model for the hydrogen atom.(E) None of the above.

17. Which of the following statements is correct?f. An excited atom can return to its ground state by emitting electromagnetic radiation.ff. The energy of an atom is increased when electromagnetic radiation is emitted from it.fff. The energy of electromagnetic radiation increases as its frequency increases.fV. An electron in the n=4 state in the hydrogen atom can go to the n=2 state by emittingelectromagnetic radiation at the appropriate frequency.V. The frequency and wavelength of electromagnetic radiation are inversely proportional toeach other.(A) f, fff, fV, V (B) fff, V (C) f, ff, fff (D) fff, fV, V (E) f, ff, fV

18. Given values of the following acids:What is the order of increasing base strength?(A)(B)(C) (D)(E)

19. The molecular formula of the ion is , where X is an element from Group 6A. What is the hybridization of X atom?(A) sp (B) sp2 (C) sp3 (D) dsp3 (E) d2sp3

20. Which ion has the largest ionic size among the following?(A) (B) (C) (D) (E)