Faculty Of Computer StudiesMS101

Physics

MTA answer key Ver. B

Fall – 2013-2014Date 16 December 2013

(2 ) HoursTime Allowed:(5)Number of Exam Pages: Instructions:

1. This exam consists of three parts: Part I: 5 Multiple Choice Questions (MCQ), of which you can choose any 4. Each is worth 2.5 marks for a to-tal of 10 marksPart II: 5 short essay questions of hich you can choose any 4. Each question is worth 10 marks for a total of 40 marks.Part III: 5 problems of which you can choose any 4. Each problem is worth 17 marks for a total of 51 marks.

2. Write all your answers in the an-swer booklet and not in this questions booklet.

3. Calculators are allowed.

Good Luck

ثالثة اجزاء:هذا االمتحان مكون من .1 اسئلة من نوع االختيار5: الجزء االول

منها و4يختار الطالب اى المتعدد مخصص لكل سؤال درجتان و نصف

درجات10باجمالى اسئلة اختبارات5: الجزء الثانى

منها و4قصيرة يختار الطالب اى درجات بإجمالى10مخصص لكل سؤال

درجة40 مسائل يختار الطالب5: الجزء الثالث

17 منها و مخصص لكل سؤال 3اى درجة51درجات بإجمالى

برجاء كتابة االجابات فى ورقة االجابة و.2ليس فى ورقة االسئلة.

يسمح باالالت الحاسبة.3

حظ سعيد

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Part I: answer ANY 4 of the following 5 Multiple Choice Questions (MCQ), each worth 2.5 marks for a total of 10 marks.

1. Find the equation x = at2 + bt that fits the following data.

A. x = 2t2 + 0B. x = 6t2 - 3tC. x = 2t2 + 2tD. x = t2 + t

2. The net force on a moving object suddenly becomes zero. The object then

A. stops abruptly.B. stops during a short time interval.C. changes direction.D. continues at constant velocity.

3. A force of 20 N pushes an object of mass 5.0 kg along a rough horizontal surface where the frictional force is 5.0 N. What is the acceleration of the object?A. 1.0 m/s2

B. 2.0 m/s2

C. 3.0 m/s2

D. 4.0 m/s2

4. You drive five blocks due north, five blocks due east, and another two blocks due north. What is the magnitude of your displacement?

A. 7 blocksB. 12 blocksC. 9 blocksD. 8.6 blocks

5. The figure is a graph of vx(t) for a car. Solve graphically for the distance traveled from t = 10 s to t = 15 s A. 75 mB. 70 mC. 67 mD. 69 m

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Part II: Answer ANY 4 of the following 5 short essay questions. Each ques-tion is worth 10 marks for a total of 40 marks.

1. A car is driving on a level highway. It is acted upon by the following forces: a downward gravitational force of 12 kN, an upward contact force due to the road of 12 kN, another con-tact force due to the road of 7 kN directed West, and a drag force due to air resistance of 5 kN directed East. What is the net force acting on the car? 

Answer:2 kN West

2. An ant travels 30 cm east, the 25 cm north, and finally 15 cm west. What is the direc-tion with respect to his starting point?

Answer:59 N of E

3. A car travels a distance of 100 km in 2.00 hours. It then travels an additional distance of 60.0 km in 1.00 hour. What is the average speed of the car for the entire trip?

Answer:53.3 km/hr

4. Using Newton’s third law determine the reaction force that goes with the frictional force of the ground acting on a case being dragged across the floor?

Answer:The frictional force of the case acting on the ground

5. Two masses are connected by a string which passes over a pulley with negligible mass and friction. One mass hangs vertically and one mass slides on a frictionless 30.0 degrees incline. The vertically hanging mass is 6.00 kg and the mass on the in-cline is 4.00 kg. Calculate the acceleration of the 4.00 kg mass?

Answer:5.88 m/s2

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m1= 20 kgm2= 10 kg

60

Part III: Answer ANY 3 of the following 4 problems. Each problem is worth 17.5 marks for a total of 51 marks.

1. Four forces act on bolt A as shown. Deter-mine the resultant of the force on the bolt.

Answer:

R = 199.6 N

Θ = 4.1o

2. The block m1 slides on a smooth incline as shown. Calculate:(a) The normal force

Answer: (a) N = 10.0 g N

3. The graph shows speedometer readings. What is the distance covered between t=3.0 s and t=8.0 s.

Answer: Calculate the area under the curve =

16.5 km.

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4. Two small steel balls A and B have mass 0.6 kg and 0.2 kg respectively. They are moving towards each other in opposite directions on a smooth horizontal table when they collide directly. Immediately before the collision, the speed of A is 8 m/s and the speed of B is 2 m/s. Immediately after the collision, the direction of motion of A is un-changed and the speed of B is twice the speed of A. Find

(a) the speed of A immediately after the collision,

(b) the magnitude of the impulse exerted on B in the collision.

Answer: (b) V = 4.4 m/s(c) I = 2.16 Ns

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