Engineering Mechanics Revision Finals Exam
Problem Sheet No. 1
1. Determine the tension in cables CA and CB.
Ans. TCA = 2870 N, TCB = 3520 N.
2. The uniform bar has a mass per unit length of 60 kg/m. Determine the reactions at the supports.
Ans. Ay = 3060 N, By = 2060 N.
3. The uniform angle bar with equal legs has a mass of 20 kg and is supported in the vertical plane as shown. Calculate the force FA supported by the pin at A.
Ans. FA = 277 N.
4. Determine the reactions at A and E if P=500 N. What is the maximum value that P may have for static equilibrium? Neglect the weight of the structure compared with the applied loads.
Ans. Ax = -1290 N, Ay = 2960 N, E x= 3290 N, P=1732 N.
Figure P.S.1.1
Figure P.S.1.2
Figure P.S.1.3
Figure P.S.1.4
A man pushes the 40 kg machine with mass centre at G up an incline at a steady speed. Determine the required force magnitude P and the normal reaction forces at A and B. Neglect the small effects of friction.
Ans. P = 112.1 N, NB = 219 N, NA = 207 N.
During an engine test, a propeller thrust T = 3000 N is generated on the 1800-kg airplane with mass centre at G. The main wheels at B are locked and do not skid; the small tail wheel at A has no brake. Compute the percent change n in the normal forces at A and B as compared with their “engine-off” values.
Ans. nA = -32.6%, nB = 2.28%
What fraction n of the weight W of a jet airplane is the net thrust (nozzle thrust T minus air resistance R) in order for the airplane to climb with a constant speed at an angle ( with the horizontal?
Ans. n = sin (
The three cables are secured to a ring at B, and the turnbuckle at C is tightened until it supports a tension of 1.6 kN. Calculate the moment M produced by the tension in cable AB about the base of the mast at D.
Ans. M = 8 kN.m
Figure P.S.1.5
Figure PS.1.6
Figure P.S.1.7
Figure P.S.1.8
1. Determine the tension in cables CA and CB.
Ans. TCA = 2870 N, TCB = 3520 N.
2. The uniform bar has a mass per unit length of 60 kg/m. Determine the reactions at the supports.
Ans. Ay = 3060 N, By = 2060 N.
3. The uniform angle bar with equal legs has a mass of 20 kg and is supported in the vertical plane as shown. Calculate the force FA supported by the pin at A.
Ans. FA = 277 N.
4. Determine the reactions at A and E if P=500 N. What is the maximum value that P may have for static equilibrium? Neglect the weight of the structure compared with the applied loads.
Ans. Ax = -1290 N, Ay = 2960 N, E x= 3290 N, P=1732 N.
Figure P.S.1.1
Figure P.S.1.2
Figure P.S.1.3
Figure P.S.1.4
A man pushes the 40 kg machine with mass centre at G up an incline at a steady speed. Determine the required force magnitude P and the normal reaction forces at A and B. Neglect the small effects of friction.
Ans. P = 112.1 N, NB = 219 N, NA = 207 N.
During an engine test, a propeller thrust T = 3000 N is generated on the 1800-kg airplane with mass centre at G. The main wheels at B are locked and do not skid; the small tail wheel at A has no brake. Compute the percent change n in the normal forces at A and B as compared with their “engine-off” values.
Ans. nA = -32.6%, nB = 2.28%
What fraction n of the weight W of a jet airplane is the net thrust (nozzle thrust T minus air resistance R) in order for the airplane to climb with a constant speed at an angle ( with the horizontal?
Ans. n = sin (
The three cables are secured to a ring at B, and the turnbuckle at C is tightened until it supports a tension of 1.6 kN. Calculate the moment M produced by the tension in cable AB about the base of the mast at D.
Ans. M = 8 kN.m
Figure P.S.1.5
Figure PS.1.6
Figure P.S.1.7
Figure P.S.1.8