8/18/2019 Midterm Intro to Mech Eng [13!11!13]

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Dr. Naser Nawayseh Fall 13_14 1

College of Engineering

Mechanical Engineering Program

Introduction to Mechanical Engineering (0408100)

Midterm

Name: Solutions Date: 13th

 November 2013

Please read the following notes before answering the test:

1.  Mobile phones must be switched off during the test.

2.  This is a closed book test.

3.  Calculators are allowed (but not mobile built in calculators)

4.  The test consists of 3 questions.

5.  The duration of the test is 60 minutes.

6. 

Write your name on all papers.

7.  Do not use pencil.

8/18/2019 Midterm Intro to Mech Eng [13!11!13]

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Dr. Naser Nawayseh Fall 13_14 2

Question 1 (9 marks)State whether the following statements are right (√) or wrong (X): 

( √  )

( X )

( X )

( X )

( √  )

( X )

( X )

( X )

( √  )

( √  )

( X )

( X )

( √  )

( X )

( X )

( √  )

( √  )

( √  )

1.  Mechanical Engineering is a field of engineering that applies mathematics, the principles of

 physics and materials science for analysis, design, manufacturing, and maintenance of systems.

2. 

Mechanical engineers work with machines that can produce or consume power in a very narrow

range.

3.  Mechanic, technician and engineer all refer to the same profession.

4.  Engineering could be defined as the intersection of activities related to mathematics, science, and

computer simulation, while hardware is not involved in this intersection of activities.

5.  Mechanical engineers can design products related to healthcare.

6.  Improvement of an existing product cannot be considered as new technology.

7.  Material selection and system simulation are performed in the conceptual design stage.

8.  When designing a product, engineers have to take into account the ergonomic concerns which

refer to the international market needs of the product.

9.  When developing a product, engineers have to take into consideration the impact on the

environment during the production, use and retirement of the product.

10. Patents provide legal protection for inventors of new technology.

11. Machining is a process in which a raw material is shaped by stretching, bending, or compression.

12. Products produced by sand casting are inexpensive and have smooth surfaces.

13. 

In extrusion process, one can create long straight metal parts whose cross sections may be round,

rectangular, L-, T-, or C-shaped.

14.  It is enough for engineers to be aware of one system of units.

15.  In the SI system of units, kg, meter and Newton are base units.

16. The prefix micro indicates a multiplicative factor of 10 -6.

17. Dimensional consistency means that the left side of an equation must have the same unit as the

right side of the equation.

18. 

The precision of a number is half as large as the place of the last significant digit in the number.

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Question 2 (11 marks)

A front loader of mass 4500 kg is shown in side view as it lifts a 750 kg load of gravel.(a) Draw a free body diagram of the front loader

(b) Determine the contact forces between the wheels and the ground.

Solution:

a)

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Dr. Naser Nawayseh Fall 13_14 4

Question 3 (10 marks)

A copper bar of a rectangular section of 20 mm × 30 mm and a length of 500 mm is subjected to an axialcompressive load of 60 kN. If  E = 102 GPa and v for copper = 0.34, determine:

(a) The stress

(b) The strain in the direction of the length

(c) The lateral strain(d) The change in length

(e) The change in the 30 mm side

Solution:

End of Paper

Good luck