15 . What is the wavelength of a 256 Hz piano note (middle-C), given that the speed of sound is 343 mfs? (5 marks) 16. What is the velocity of a wave that makes 10 complete oscillations in 15 s and has a wavelength of 050 m? (5 marks) 17. What is the wavelength of a shock wave that travels at 840 ms and has a frequency of 4.5 Hz? (5 marks) 13. A 40.0 kg object is being acted on simultaneously by a 110.0 N[E60N] force, a 40.0 N [S] force, and finally, a 50.0 N[E2T"S] force. (a) Find the resultant force (net force) acting on the object, and its acceleration. (6 marks) (b) What is the object's velocity after 7.0 s, assuming that it started from rest? (5 marks) 14. Circle T: True, or F: False. Rewrite the false statements to make them true. (4 marks) (a) The gravity force will determine the ultimate fate T or F of the universe. (b) The mathematical expression F = ma represents Newton's T or F second law. (c) The force of friction is dependent on the area of contact. T or F (d) A contact force is exerted only when two objects are touching. T or F 601510