# Physics Principles and Problems 2009

## Chapter 14: Vibrations and Waves

### Chapter Test Practice

 1 The formula represents the period of a pendulum, T. What is the period of a 3.5 m-long pendulum on Earth? (1.0K) Need a Hint? A) 3.2 s B) 4.6 s C) 3.8 s D) 1.4 s 2 In the figure below, if the spring's constant is 20.0 N/m and x has a value of 0.25 m, what is m equal to? (9.0K) Need a Hint? A) 0.06 kg B) 0.63 kg C) 0.51 kg D) 5.0 kg 3 In the figure below, if you doubled the mass of the pendulum, what effect, if any, would it have on its period? (6.0K) Need a Hint? A) The new period would be half the old period. B) The new period would be the old period, divided by the square root of two. C) The new period would be the old period, times the square root of two. D) It would have no effect. 4 In the figure below, if the scale of the graph is 1 block = 10 N on the vertical axis and one block = 2 cm on the horizontal axis, what is the spring constant? (6.0K) Need a Hint? A) 500 N/m B) 250 N/m C) 5 N/m D) 20 N/m 5 In the figure below, if you quadrupled the length of the string, what effect, if any, would it have on its period? (6.0K) Need a Hint? A) The period would be halved. B) The period would be doubled. C) It would have no effect. D) The period would be quadrupled. 6 If a wave's frequency increases, its period __________. Need a Hint? A) fluctuates B) remains the same C) decreases D) increases 7 Mechanical waves require __________. Need a Hint? A) a gas B) a solid C) a medium D) a vacuum 8 What mathematical expression relates frequency to period? Need a Hint? A) f = 1/T B) 1/f = 1/T C) f = 2T D) f = T 9 In the figure below, how much time elapses between pictures a and c? (24.0K) Need a Hint? A) 25 s B) 0.02 s C) 0.04 s D) Not enough information is given to answer this question. 10 A wave with a frequency of 10 Hz and a wavelength of 2 m has a speed of __________. Need a Hint? A) 20 m/s B) 0.2 m/s C) 5 m/s D) 2 m/s 11 The __________ of a wave can be used to determine how much energy is being transferred by the wave. Need a Hint? A) speed B) frequency C) period D) amplitude 12 What does a wave carry? Need a Hint? A) matter B) particles C) energy D) heat 13 Surface waves move in a position __________ to the direction of the wave motion. Need a Hint? A) both parallel and perpendicular B) in a circular motion relative C) parallel D) perpendicular 14 A single bump or disturbance that travels through a medium is a ___________. Need a Hint? A) wave pulse B) surface wave C) compressional wave D) continuous wave 15 In Figure 14-14, how do the frequencies of the waves in pictures a and c compare? (20.0K) Need a Hint? A) a's frequency is twice c's. B) a's frequency is four times c's. C) a's frequency is half of c's. D) a's frequency is one-quarter of c's. 16 A trough is __________ of a wave. Need a Hint? A) the starting point B) the midpoint C) the low point D) the high point 17 A pulse traveling along a bullwhip is an example of a __________ wave. Need a Hint? A) surface B) longitudinal C) compressional wave D) transverse 18 The speed of a wave depends on the __________. Need a Hint? A) frequency B) medium C) energy D) amplitude 19 A(n) __________ is a line perpendicular to a reflective surface. Need a Hint? A) incidence B) reflection C) normal D) angle 20 Waves become inverted if they reflect off a medium that is __________ than the initial medium. Need a Hint? A) less dense B) softer C) more gaseous D) more dense 21 The principle of superposition states that __________. Need a Hint? A) waves from different mediums can combine to form a new wave B) the energy of a wave depends on its position C) waves can never combine D) two or more waves can combine to form a new wave 22 The superposition of waves with equal but opposite amplitueds causes __________. Need a Hint? A) constructive interference B) consonance C) dissidence D) destructive interference 23 When a continuous wave meets a boundary that transmits the wave at a lower speed, the wavelength __________. Need a Hint? A) increases B) decreases C) interferes with itself D) becomes negative 24 A standing wave appears to be __________. Need a Hint? A) moving very fast B) fluctuating C) standing still D) moving very slowly 25 When a wave pulse strikes a wall, it reflects back and is __________. Need a Hint? A) changed from compressional to transverse B) inverted C) amplified D) reduced to zero 26 __________ is the point of the largest displacement where two waves meet. Need a Hint? A) A node B) A period C) A crest D) An antinode 27 A wave that reflects off a flat surface will reflect at __________. Need a Hint? A) a different angle from which it struck the surface B) an angle of zero C) the same angle at which it struck the surface D) a right angle to the surface 28 __________ is the change in direction of a wave when it intersects a boundary between two different media. Need a Hint? A) Refraction B) Diffusion C) Diffraction D) Reflection 29 A __________ wave bounces off a boundary. Need a Hint? A) incident B) surface C) transverse D) reflected