Reference no: EM132190738

Question: Test 3: Take Home 2018

Instructions: 1. All work must be shown.

2. No answers will be accepted without showing the process used to get the answer.

3. The process(setup) is a large part of the grade. I need to see easily how you got your answer.

4. If a formula is used, write out the formula in symbols before any algebra or numbers are used.

5. Do not use derived formulas that are problem specific. Start with the basic physics equations or concepts.

6. Follow the rules for significant figures but don't be fanatical.

7. Label and box your final answers.

g = 9.80 m/s2 on the earth's surface. In all cases ignore air resistance.

1. To enable the proper sealing of a submarine door a hydraulic system is used. See diagram below. The force desired on the left hand cylinder is 5000.N and the radius is 35.0cm

a. What must the force be on the right cylinder which is 15.0cm in diameter?

b. When the right cylinder moves 5.00cm, how far does the left cylinder move?

c. What pressure is in the system?

2. A submarine dives to a depth of 55.0m in seawater (density = 1025 kg/m3).

a. What is the water pressure (gauge) on the submarine?

b. In order to surface, water is pushed out of a ballast tank at a rate of 50.0gallons/min. Convert this to a mass flow rate in kg./m3.
Note: 1 gal. = .00378541 m3

c. If the diameter of the outlet is 45.0cm, what is the speed of the water through the outlet?

d. Use the Bernoulli equation to determine the pressure value inside the tank? Assume the tank is large so the water speed in the tank is essentially 0.

3. Due to bravery in underwater combat you are given a medal supposedly made of pure gold. The medal weighs 8.30N. in air. You suspend the medal by a string so that it was completely immersed in in seawater (density = 1025 kg/m3). The tension in the string was 7.81N. when suspended in the seawater.

a. Show a free body diagram of the medal in the water. Label the buoyant force Fb.

b. Determine the buoyant force.

c. Use the buoyant force to find the volume of the medal.

d. What is the density of the medal?

e. Is the medal gold? Support your answer.

4. While sitting on the surface the waves cause resonance and the submarine starts swinging left and right in simple harmonic motion like a pendulum on an X-axis. You find that you it takes
2.50 seconds to do 2 complete oscillations (cycles). You also estimate that the boat swings to the side 0.40 m from the equilibrium position about the axis of rotation.

a. What are the period, frequency, and angular frequency ??

b. What is the maximum speed of the SHM?

c. If you start your clock at the positive amplitude write the equation for this SHM.

d. What is the position at 0.600 seconds?

e. What is the speed at .600 seconds?

5. The following figure is a graph of an ocean water wave at a fixed position. The second following figure is a graph of the same wave at a fixed time.

a. What is the period?

b. What is the frequency in Hz?

c. What is the angular frequency?

d. What is the wavelength?

e. What is the wave speed?

f. What is the amplitude?

g. Write the equation for this wave in the form y = Asin(?t +or- kx) where t and x are the variables. Assume the wave is moving in the +X direction.

6. The speed of sound in seawater is approximately 1480 m/s. You are at a depth of 50.0m

a. You ping the ocean bottom and receive the echo back 0.125 seconds later. How deep is the ocean at this point?

b. If the frequency of the sound is 500.0 Hz, what is the wavelength of the sound?

c. The ping coming back to the submarine has an intensity of as -80.0 dB. What is the intensity of the returning sound wave?

d. Use the distance in part (b) and the answer in (c) to find the power of the reflected sound.

7. A bosun's whistle is 9.000 cm long and is open at both ends. It is used on the ship and thus in air. The temperature of the air is 20.00 oC. at the whistle's location. The speed of sound in air is [331 + .606×oC] m/s. Note: Use 4 significant digits for the speed of sound in this problem.

a. What is the wavelength of the fundamental frequency of the whistle?

b. What is the fundamental frequency?

c. Another whistle is blown but its length is only 8.950cm and it is also open at both ends. What is the beat frequency between the fundamental modes of the two whistles?

8. Active sonar is used to determine the speed of an oncoming submarine. You send out a signal with a frequency of 500.0Hz. Your submarine is traveling at 13.0 m/s and the enemy is coming towards you at 9.00 m/s. Use the wave i.e. speed of sound as 1480m/s.

a. What frequency will be reflected off the enemy?

b. What frequency will be received by your submarine from the reflection?

c. The enemy stops and sends his own signal of 600.0Hz. You receive his signal at what frequency? You are still moving towards him.

Note: Please see attached file for teh diagrams and tables.

Information related to above question is enclosed below:

Attachment:- Test3takehome2018.rar