Page 1/3 XXXXXXXXXXAUCKLAND INSTITUTE OF TECHNOLOGY Name
MEP-A/Statics/2020
XXXXXXXXXXID Number: ____________
First Name: _______________________ Family Name: _____________________
Online Assessment 2
June 19, 2020
Statics
Total 26 marks
Read the following carefully
Â· You have four questions in this booklet. Answer ALL questions
Â· If you have access to a Tablet PC, you can download a copy of this word file and directly solve each question in the space provided using a digital pen.
Â· If you do not have access to a tablet PC, solve each question on pieces of paper. Then either scan (if a scanner is readily available) or use your mobile phones to take photos or scan the answer into digital images.
Â· Copy the images into the appropriate spaces against each question in the word file of this booklet again.
Â· Also type your name and student ID at the allocated spaces on the front page of this digital booklet.
Â· Save the solved version of the booklet as a pdf and name it as: Statics_Assignment2_yourname.pdf
Â· Upload the pdf into Blackboard through Turnitin before 6.00 pm on the day of assessment.
Question 1
Three blocks A, B, and C are connected through a rope and pulley system to slide on the sloping surfaces on either side of the wedge as shown in Fig. 1. The mass of A is 3 kg and that of B is 2 kg. The coefficient of friction at the interface between A and B is Âµ1 = 0.5 and that between B and the left slanting surface is Âµ2 = 0.1. Calculate the limiting values of the mass of the block C for the following conditions.
(a) Block A begins to slide upwards over block B, which is stationary.
(b) Block A and B begin to slide together downwards
(c) Block A begins to slide downwards relative to block B. Also, state what will be the condition of B at this stage, moving? or stationary?
Please note, you must draw co
ect free body diagrams for each of the cases individually. Also, neglect the weights of pulleys and the rope and any friction at the pulleys and the supporting wheels of mass C.
[6 Marks]
Fig. 1
Question 2
Calculate the X- and Y- coordinates of the centroid of the shaded area shown in Fig. 2. Please note that the equation of the curve is defined with reference to the local coordinate axes xâ€˜ and yâ€˜. [6 Marks]
Fig. 2
Question 3
A compound plane truss is loaded as shown in Figure 3. The loads at joints L and N are acting along the directions of members LS and NR, respectively. Also, all distances shown are in metres.
(a) Calculate the reaction forces at A and P
(b) Identify all the zero force members that can be immediately identified and list them clearly
(c) Calculate the forces in members EF, EY, and ZY and state whether each of them is in Tension or Compression
(d) Calculate the forces in the members MN, MR, and SR and state whether each of them is in Tension or Compression [7 Marks]
Fig. 3
Question 4
Calculate the moment of inertia of the shaded area shown in Fig 4 about the X-axis. Please note, the equations of the curves are given with reference to the local axes xâ€™ and yâ€™. If you find it convenient, you may refer to these axes as x- and y-, while dealing with the calculation of the moment of inertia of the area enclosed between the two curves and the two vertical lines with reference to the local axes and use appropriate signs for the equations of the curves. [7 Marks]
Fig. 4
1