UNIVERSITI MALAYSIA PERLIS
Peperiksaan Buku Terbuka Kedua
Semester 2 Sidang Akademik 2021/2022
Julai 2022
EMJ 17203–Engineering Dynamics
[Dinamik Kejuruteraan]
Masa: 1 jam 30 minit
Name: AHMED FAISAL GHANDOR MUBARAK
Matric number: 211060015-5
Please make sure that this question paper has SIX (6) printed pages including this front
page before you start the examination.
[Sila pastikan kertas soalan ini mengandungi ENAM (6) muka surat yang bercetak termasuk muka hadapan
sebelum anda memulakan peperiksaan ini.]
This question paper has FOUR (4) questions. Answer ALL questions. Total mark is 60
marks.
[Kertas soalan ini mengandungi EMPAT (4) soalan. Jawab SEMUA soalan. Jumlah markah adalah 60.]
(EMJ 17203)
-2SULIT
Question 1
[Soalan 1]
(a)
Planar motion of a body occurs when all the particles of a rigid body move along
paths which are equidistant from a fixed plane. Name four (4) types of a rigid body
planar motion as shown in Figure 1. Based on your understanding, explain all these
types of motion.
[Pergerakan satah suatu badan berlaku apabila semua zarah jasad pegun bergerak sepanjang laluan
dimana jaraknya sama daripada satah tetap. Namakan empat (4) jenis pergerakan oleh jasad pegun
seperti yang ditunjukkan dalam Rajah 1. Berdasarkan pemahaman kamu, terangkan kesemua jenis
pergerakkan ini.]
(4 Marks/ Markah)
Figure 1
[Rajah 1]
(EMJ 17203)
-3SULIT
(b)
Figure 2 shows pully A is given a constant angular acceleration 𝛼𝐴 = 5 rad/sec2 at the instant
𝜔𝐴 = 7 rad/s. Determine the magnitude of acceleration of point B on pully C when A rotates
2 revolutions. Pully C has inner hub which is fixed to outer one and turns with it.
[Rajah 2 menunjukkan takal 𝐴 diberi pecutan sudut malar 𝛼𝐴 = 5 rad/saat2 pada saat 𝜔𝐴 = 7 rad/s.
Tentukan magnitud pecutan di titik 𝐵 pada takal 𝐶 apabila 𝐴 berputar sebanyak 2 pusingan. Takal 𝐶
mempunyai alur dalam yang dipasang pada bahagian luarnya dan berpusing dengannya.]
(6 Marks/ Markah)
Figure 2
[Rajah 2]
(EMJ 17203)
-4SULIT
Question 2
[Soalan 2]
(a)
Describe and elaborate the difference between Kinematics and Kinetics.
[Terangkan dan huraikan perbezaan antara Kinematik dan Kinetik.]
(4 Marks/ Markah)
(b)
Determine the mass moment of inertia of the tin plate about an axis that perpendicular
to the page and passing through point 𝑂 as shown in Figure 3. The material has a
mass per unit area of 16 kg/m2.
[Tentukan momen jisim inersia plat timah terhadap paksi yang bersudut tegak dengan halaman muka
surat dan melalui titik 𝑂 seperti yang ditunjukkan dalam Rajah 3. Bahan tersebut mempunyai jisim
per unit luas 16 kg/m2.]
(6 Marks/ Markah)
Figure 3
[Rajah 3]
(EMJ 17203)
-5SULIT
Question 3
[Soalan 3]
Figure 4 shows a forklift is lifting a crate. The mass of the forklift including the driver is
1.3 Mg and the mass of the crate is 104 kg. The forklift lifts the crate with an acceleration
of 6 m/s2. Note that the centers of mass of the forklift and the crate are at G and C,
respectively.
[Rajah 4 menunjukkan sebuah pengangkut sedang mengangkat sebuah peti. Jisim pengangkut termasuk
pemandu ialah 1.3 Mg dan jisim peti ialah 104 kg. Pengangkut itu mengangkat peti dengan pecutan 6 m/s2.
Diberi pusat jisim untuk pengangkut dan peti itu masing-masing berada pada G dan C.]
(a)
Draw the free body diagram and kinetic diagram of the system.
[Lukis gambar rajah jasad bebas dan gambar rajah kinetik bagi system tersebut.]
(4 Marks/ Markah)
(b)
Determine the normal reaction forces at each of the two wheels at A and B.
[Tentukan daya tindak balas normal pada setiap dua roda di A dan B.]
(12 Marks/ Markah)
(c)
If the rear-wheel drive forklift is moving to the right and achieve a constant
acceleration starting from rest, evaluate the minimum time needed to achieve a speed
of 9 m/s. The coefficient of static friction between the wheels and the road surface is
μs = 0.8. The front wheels are free to rotate. Neglect the mass of the wheels.
[Jika pengangkut pacuan roda belakang tersebut bergerak ke kanan dan mencapai pecutan malar
bermula dari pegun, tentukan masa yang diperlukan untuk mencapai kelajuan 9 m/s. Pekali geseran
statik antara roda dan permukaan jalan ialah μs = 0.8. Roda hadapan adalah bebas berputar. Abaikan
jisim roda.]
(4 Marks/ Markah)
Figure 4
[Rajah 4]
(EMJ 17203)
-6SULIT
Question 4
[Soalan 4]
Figure 5 shows a 45-kg wheel is mounted to the link Z with mass center at G. The wheel
is released from rest in the horizontal position at A and rolling down on the circular surface
without slipping. The radius of gyration of the wheel about its mass center is kG = 0.33 m.
Neglect the mass of link Z.
[Rajah 5 menunjukkan sebuah roda 45 kg yang dipasang pada penghubung Z dengan pusat jisim di G. Roda
itu dilepaskan daripada pegun dalam kedudukan mengufuk di A dan bergolek ke bawah di atas permukaan
bulat tanpa gelincir. Jejari kilasan roda mengenai pusat jisimnya ialah kG = 0.33 m. Abaikan jisim
penghubung Z.]
(a)
Describe two forces that do no work in the system. Explain the reason.
[Terangkan dua daya yang tidak berfungsi di dalam system tersebut. Jelaskan sebabnya.]
(4 Marks/ Markah)
(b)
Compute the angular velocity of the wheel when it reaches B.
[Hitung halaju sudut roda apabila ia tiba di B.]
(8 Marks/ Markah)
(c)
If a couple moment of M = 789 N∙m is applied to link Z in counter clockwise direction,
evaluate the resulted value of angular velocity of the wheel when it reaches B.
[Jika pasangan momen M = 789 N∙m diaplikasikan pada pautan Z mengikut arah lawan jam, nilaikan
halaju sudut roda apabila ia tiba di B.]
(8 Marks/ Markah)
Figure 5
[Rajah 5]