MCQOPTIONS
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MCQOPTIONS
This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering Mechanics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If the cable CB is horizontal and the beam is at rest in the position shown, determine the tension in the cable at the instant the towing force F = 1500 N is applied. The coefficient of friction between the beam and the floor at A is A = 0.3. For the calculation, assume that the beam is a uniform slender rod having a mass of 100 kg. |
| A. | TCB = 636 N |
| B. | TCB = 1206 N |
| C. | TCB = 1016 N |
| D. | TCB = 347 N |
| Answer» B. TCB = 1206 N | |
| 2. |
A cord wrapped around the inner core of a spool. If the cord is pulled with a constant tension of 30 lb and the spool is originally at rest, determine the spool's angular Velocity when s = 8 ft of cord have unraveled. Neglect the weight of the cord. The spool and cord have a total weight of 400 lb and the radius of gyration about the axle A is kA = 1.30 ft. |
| A. | = 6.73 rad/s |
| B. | = 3.38 rad/s |
| C. | = 4.78 rad/s |
| D. | = 11.43 rad/s |
| Answer» D. = 11.43 rad/s | |
| 3. |
A woman sits in a rigid position on her rocking chair by keeping her feet on the bottom rungs at B. At the instant shown, she has reached an extreme backward position and has zero angular velocity. Determine her forward angular acceleration and the frictional force at A necessary to prevent the rocker from slipping. The woman and the rocker have a combined weight of 180 lb and a raduis of gyration about G of kG = 2.2 ft. |
| A. | = 1.185 rad/s2, F = 19.87 lb |
| B. | = 1.143 rad/s2, F = 19.16 lb |
| C. | = 1.163 rad/s2, F = 19.51 lb |
| D. | = 3.16 rad/s2, F = 5301 lb |
| Answer» C. = 1.163 rad/s2, F = 19.51 lb | |
| 4. |
The 15-lb rod is pinned and has an angular velocity of = 5 rad/s when it is in the horizontal position shown. Determine the rod's angular acceleration and the pin reactions at this instant. |
| A. | = 16.1 rad/s2, Ax = 17.47 lb, Ay = 3.75 lb |
| B. | = 64.4 rad/s2, Ax = 17.47 lb, Ay = 30.0 lb |
| C. | = 16.1 rad/s2, Ax = 17.47 lb, Ay = 15.00 lb |
| D. | = 64.4 rad/s2, Ax = 17.47 lb, Ay = 15.00 lb |
| Answer» B. = 64.4 rad/s2, Ax = 17.47 lb, Ay = 30.0 lb | |
| 5. |
Bar AB has a weight of 10 lb and is fixed to the carriage at A. Determine the internal axial force Ay, shear force V, and moment MA at A if the carriage is descending the plane with an acceleration of 4 ft/s2. |
| A. | Ay = 8.92 lb 8, Vx = 0.621 lb 7, MA = 0 |
| B. | Ay = 9.38 lb 8, Vx = 1.076 lb 7, MA = 1.076 lb-ft |
| C. | Ay = 8.92 lb 8, Vx = 0.621 lb 7, MA = 0.621 lb-ft |
| D. | Ay = 9.38 lb 8, Vx = 1.076 lb 7, MA = 0 |
| Answer» C. Ay = 8.92 lb 8, Vx = 0.621 lb 7, MA = 0.621 lb-ft | |
| 6. |
The wheel has a weight of 30 lb, a radius of r = 0.5 ft, and a radius of gyration of kG = 0.23 ft. If the coefficient if friction between the wheel and the plane is = 0.2, determine the wheel's angular acceleration as it rolls down the incline. Set = 12°. |
| A. | = 59.5 rad/s2 |
| B. | = 8.93 rad/s2 |
| C. | = 11.05 rad/s2 |
| D. | = 63.3 rad/s2 |
| Answer» D. = 63.3 rad/s2 | |
| 7. |
A clown, mounted on stilts, loses his balance and falls backward from the position, where it is assumed the = 0 when = 07deg;. Paralyzed with fear, he remains rigid as he falls. His mass including the stilts is 80 kg, the mass center is at G, and the radius of gyration about G is kG = 1.2 m. Determine the coefficient of friction between his shoes and the ground at A if it is observed that slipping occurs when = 30°. |
| A. | = 0.833 |
| B. | = 0.468 |
| C. | = 0.243 |
| D. | = 0.400 |
| Answer» E. | |
| 8. |
The disk has a mass of 20 kg and is originally spinning at the end of the massless strut with an angular velocity of = 60 rad/s. If it is then placed against the wall, for which A = 0.3, determine the time required for the motion to stop. What is the force in strut BC during this time? |
| A. | t = 3.11 s, FBC = 193.1 N |
| B. | t = 2.65 s, FBC = 227 N |
| C. | t = 5.30 s, FBC = 227 N |
| D. | t = 6.21 s, FBC = 193.1 N |
| Answer» B. t = 2.65 s, FBC = 227 N | |
| 9. |
The dragster has a mass of 1.3 Mg and a center of mass at G. If a braking parachute is attached at C and provides a horizontal braking force FD, determine the maximum deceleration the dragster can have upon releasing the parachute without tipping the dragster over backwards (i.e., the normal force under the wheels and assume that the engine is disengaged so that the wheels are freely rolling. |
| A. | a = 16.35 m/s2 |
| B. | a = 8.46 m/s2 |
| C. | a = 2.75 m/s2 |
| D. | a = 35.0 m/s2 |
| Answer» B. a = 8.46 m/s2 | |
| 10. |
If the support at B is suddenly removed, determine the initial reactions at the pin A. The plate has a weight of 30 lb. |
| A. | Ax = 22.5 lb, Ay = 7.5 lb |
| B. | Ax = 0, Ay = 30.0 lb |
| C. | Ax = 11.25 lb, Ay = 18.75 lb |
| D. | Ax = 11.25 lb, Ay = 41.3 lb |
| Answer» D. Ax = 11.25 lb, Ay = 41.3 lb | |
| 11. |
The 10-kg block rests on the platform for which = 0.4. If at the instant shown link AB has an angular velocity = 2 rad/s, determine the greatest angular acceleration of the link so that the block doesn't slip. |
| A. | = 6.35 rad/s2 |
| B. | = 2.62 rad/s2 |
| C. | = 1.016 rad/s2 |
| D. | = 3.46 rad/s2 |
| Answer» D. = 3.46 rad/s2 | |
| 12. |
The sports car has a mass of 1.5 Mg and a center of mass at G. Determine the shortest time it takes for it to reach a speed of 80 km/h, starting from rest, if the engine only drives the rear wheels, whereas the front wheels are free rolling. The coefficient of friction between the wheels and road is = 0.2. Neglect the mass of the wheels for the calculation. |
| A. | t = 17.49 s |
| B. | t = 18.12 s |
| C. | t = 18.76 s |
| D. | t = 22.7 s |
| Answer» B. t = 18.12 s | |
| 13. |
The slender 200-kg beam is suspended by a cable at its end as shown. If a man pushes on its other end with a horizontal force of 30 N, determine the initial acceleration of its mass center G, the beam's angular acceleration, and the tension in the cable AB. |
| A. | aG = 0, = 0.225 rad/s2, T = 1.962 kN |
| B. | aG = 0.0750 m/s2, = 0.1125 rad/s2, T = 1.962 kN |
| C. | aG = 0, = 0.1125 rad/s2, T = 1.962 kN |
| D. | aG = 0.1500 m/s2, = 0.225 rad/s2, T = 1.962 kN |
| Answer» E. | |