# Answer: Element 011: MOD005409 Assessment

**Element 011: MOD005409 Assessment**

**Instructions to Students: Element 011: MOD005409 Assessment**

**Answer All SIX questions****The reflective parts for each question have 6 marks and limited to 50 words. This is about capturing concise/key conceptual understanding; exceeding word limit for this part will result in penalisation and your reflective writing will be marked out of 3****The data for some questions must be taken from your SID. Not complying to the instructions provided in each question, will result in mark reductions.****The deadline will be stated on the Canvas assignment page****This work will be submitted to Turnitin****Marks have been allocated individually to each question, adding to 100**

**Question 1:**** **

Elaborate and Draw the Bode diagram for the following transfer function shown in Figure.Q1 through:

(a) Showing transfer function for separate parts,

(2 marks)

(b) Drawing the Bode diagram for each part,

(3 marks)

(c) Drawing the overall Bode diagram.

(5 marks)

**Figure.Q1**

Provide a reflective commentary underpinning the KEY conceptual elements in solving this problem (maximum 50 words, 6 Marks)

(Total 16 marks)

**Question 2**

(a) A system has a pair of complex conjugate poles p_{1} and p_{2} = -1+j2 and -1-j2 respectively and a single real zero z_{1} = -4 and a gain factor k = 3. Explain how to find the differential equation representing the system.

(5 marks)

(b) Explain and Identify the common terms in transient response characteristics of control system and specify the accepted limits in each transient response

(3 marks)

c) Explain by drawing the concepts of different types of damping types in relation to the natural angular velocity.

(3 marks)

Provide a reflective commentary underpinning the KEY conceptual elements in solving this problem (maximum 50 words, 6 Marks)

(Total Question Mark: 17)

**Question 3**

Discuss how you calculate the following step response and complete the table next to it according to the measurement results as shown on each axis:

(9 marks)

Provide a reflective commentary underpinning the KEY conceptual elements in solving this problem (maximum 50 words, 6 Marks) (Total 16 marks)

**Question 4**

**1.**A mass m is held up by a force F_{0}sin(Ѡt) and connected to a spring and a damping coefficient c with the ground. The following parameters are known: the mass m = 100kg, the spring stiffness k = 700x10^{3}N/m, the peak force F_{0}= 350 N. If the revolution speed is 300 RPM and the damping ratio is 0.2, find the followings:

(a) Displacement amplitude X (6 marks)

(b) Transmissibility ratio TR = F_{T}/F_{0 }(4 marks)

(c) Magnitude of transmitted force F_{T} (4 marks)

Provide a reflective commentary underpinning the KEY conceptual elements in solving this problem (maximum 50 words, 6 Marks)

(Total 20 marks)

**Question 5**

A top-loading washing machine executes the spin cycle at 4 rotations per second. The mass of the drum is 10 kg and it has a diameter of 0.6 m. The stiffness and damping coefficient of the mount are 379 N/m and 37.7 N.s/m respectively. If the mass of clothes is 5 kg. If the clothes are in the same place in one side of the drum, calculate:

(a) The damping frequency and the natural frequency (3 marks)

(b) the damping ratio (3 marks)

(c) Vibration amplitude (3 marks)

(d) Transmitted force (3 marks)

(Total 18 marks)

**Question 6**

(a) A 160-gram object attaches at one end of a spring and the change in length of the spring is 4 cm. What is the change in length of three springs connected in series and parallel, as shown in the figure below if the three springs have the same constant, k = 40 N/m. Take the gravity acceleration as 10 m/s^{2}.

(6 marks)

(Total 13 marks)

**End of Questions: **

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