SHS AP PHYSICS SOUND’S GOOD TO ME HW PACKET HW 11A It is Springs time again- Catch a Wave (Read 11.1-11.3) 1. A 255 g mass is hooked up to a spring (k = 175 N/m) and moves back and forth on a basic frictionless surface. If the mass is released from rest at x = 0.200 m, (a) find the force acting on the mass, (b) the max acceleration, (c) acceleration at x = 0m, (d) energy at x = 0m (e) its period (f) the velocity at 0.1m. 2. A 355 g mass is attached to a spring (k = 435 N/m). If the system is allowed to oscillate on a frictionless surface, what is the period and frequency of the motion 3. Using this graph of position vs time for the simple harmonic motion of a weight on a string, find (a) the amplitude of the motion, (b) the period of the motion, (c) the frequency of the motion (d) place on the graph where the velocity is zero, (e) places on the graph where the acceleration is max and min, (f) places on the graph where the kinetic energy is max, (g) places on the graph where the potential energy is max. 4. A wave has a frequency of 262 Hz. What is the time interval between successive wave crests? 5. The drawing shows a transverse wave’s displacement vs distance graph. The wave is travelling at a speed of 2.50 m/s. Determine: (a) the wavelength, (b) the frequency of the wave, (c) the amplitude of the wave. 6. A fisherman’s scale stretches 3.6cm when a 2.7kg fish hangs from it. A young child come up and pulls the fish down 2.5cm further and releases it. Find a) the k value for the spring b) how amplitude of the vibration as the fish moves up and down c) the frequency as the fish moves up and down. 7. A mass of 2.62 kg stretches a vertical spring of 0.315. If the spring is stretched an additional 0.130m and released, how long does it take to reach the (new) equilibrium position again?

HW 11B Pendulums –Just Try and Take a Swing Sucker (Read 11.4) 1. A 165 g plastic block is set up against a spring. The block rests on a smooth horizontal surface. The block is

pushed into the spring, compressing it a distance of 15.0 cm and then released. The spring constant is k = 677 N/m. (a) What is the speed of the block when it leaves the spring? (b) If the table is 0.875 m in height, what horizontal distance does the block travel after it leaves the table edge?

2. Draw a picture of a pendulum showing its swing. Label the following points: (a) point of maximum velocity, (b) point of minimum velocity, (c) point where the potential energy is greatest, (d) point where kinetic energy is greatest, (e) if the period of the pendulum is 0.750 seconds, what is its length? (f) What is the speed of the pendulum at the bottom of its swing if the angle that the thing makes at its maximum displacement is 11.0°?

3. A pendulum has a period of 0.56 s. What is the length of the pendulum? 4. You spot a large pendulum that is swinging through a small arc. If the length of the pendulum is 5.5 m, what

is the period of the thing? 5. You are designing a pendulum clock. You have determined that the pendulum must have a period of

0.500 s. What should be the length? 6. Two masses are set up as shown. The angle θ that m1 makes with

the vertical is 38.0°. m1 is 552 g, m2 is 455 g. m1 is released, swings down and collides with the other mass. At the point of impact, the string holding up m1 is vertical and it hits the other ball head on. m1 ends up with a velocity to the right of 0.500 m/s. Find: (a) the potential energy of m1 relative to the top of the table, (b) the speed of m2 after the collision, (c) the distance x that the ball travels before it hits the deck, and (d) the kinetic energy of m2 just before it hits the deck.

Y

X

75.0 cm

15.0 cm

X (m)

t (s)O

.15

.10 .30 .50 .70

x

85.0 cm

95.0 cm

m1m2

HW 11C I’m Running Interference For You (Read 11.7,11.8,11.11-11.13) 1. A fisherman notices that a wave crests pass the bow of this anchored boat every 3.0s. He measures the

distance between crests to be 6.5m. How fast are the waves traveling? 2. A sound wave in air has a frequency of 262Hz and travels with a speed of 345m/s. How far apart are the

compressions (wave crests)? 3. A long spring runs across the floor. A pulse is sent along the spring. After a few seconds, an inverted pulse

returns. Is the spring attached to the wall or lying loose on the floor? Why? 4. Draw a picture of two waves that display destructive interference. 5. Create a depiction of a standing wave. Point out the nodes and antinodes. 6. Sketch a series of standing waves on a string between two solid points. Show the first three

harmonics. 7. A splendid light wave has a wavelength of 580 nm. What is the frequency of the wave (use speed of light)?

HW 12D Strums and Toots (Read 12.3,12.4,12.6) Assume non-standard day where 345m/s for speed of sound

Strings: 1. If a violin string vibrates t 440Hz as its fundamental frequency, what are the frequencies of the first

four harmonics. 2. A particular string resonates in four loops at a frequency of 280Hz. Name at least three other

frequencies at which at which it will resonante. 3. A violin string vibrates at 294Hz when unfingered. At what freq will it vibrate if it is fingered one-

third of the way down (hint: only 2/3 of the length of the string vibrates as a standing wave.) 4. If two successive overtones of a vibrating string are 280Hz and 350Hz, what is the frequency of the

fundamental. Tubes:

5. A pipe is 18.5 cm long and closed on one end. (a) What are the frequencies of the first three harmonics that resonate in the pipe? (b) What is the wavelength of the third harmonic?

6. A pipe is 155 cm long and open on both ends. (a) What are the frequencies of the first three harmonics that resonate in the pipe? (b) What is the wavelength of the first harmonic?

HW 12E Speeding Tickets & Dopplers Stink (Read 12.7,12.8) Assume non-standard day where 345m/s for speed of sound

1. You are at a stop light in your car, stuck behind a red light. Just before the light is supposed to change, a fire engine comes zooming up towards you traveling at a horrendous 85.0 km/h. If the siren has a rated frequency 665 Hz, (a) what frequency do you hear? (b) what is the wavelength of the sound you hear?

2. You are on a train traveling at 105 km/h. You approach a stationary 455 Hz siren. What is frequency you hear?

3. You are on a train traveling at 55.0 km/h. You approach a bell. The actual frequency of the bell is 725 Hz. What frequency do you hear?

4. An FM radio station’s basic frequency has a wavelength of 2.67 m. What is its frequency? 5. A 1250 kg car has 3 passengers with a combined mass of 135 kg. The car has four identical springs

that have a spring constant of 18 500 N/m. (a) Find the frequency of vibration for the car when it goes over the old speed bump. (b) How much time does it take for the car to go through 2 oscillations?

11A 1a)-35.0N b) -137m/s c) 0 d) 3.5J e)0.240s f) 4.53m/s 2a) 5.59 Hz b) 0.179 s 3a-g) we’ll go over in class 4)3.82 ms 5a) 0.750m b) 3.3 Hz c) A=0.15m 6a) 735 N/m b) 2.5cm c) 2.6 Hz 7) 0.282s

11B 1a) 9.61m/s b) 4.06m 2e) 0.140m g) 0.225m/s 3) 0.078m 4) in class 5) 0.0621m 6a) 0.975J b) 2.89m/s c) 1.27m d) 6.14J

11C 1) 2.2m/s 2) 1.32m 3-6) In Class 7) 5.17E-14Hz 12D 1) 440/880/1320/1760 Hz 2) 70/140/210Hz 3) 441Hz 4) 70 Hz 5a) 2330 Hz b) 0.148m

6a) 111.2/222.4/333.6Hz b) 3.10 m 12E 1a) 703Hz b) 0.491m 2) 493 Hz 3) 759 Hz 4) 1.12E8 Hz 5a) 1.16 Hz b) 1.72s