Explore topic-wise MCQs in Engineering.

The 12-kg disk has an angular velocity of = 20 rad/s. If the brake ABC is applied such that the magnitude of force P varies with time as shown, determine the time needed to stop the disk. The coefficient of friction at B is = 0.4.

Determine the force in members GF, CF, CD of the symmetric roof truss and indicate whether the members are in tension or compression.

Determine the minimum force F needed to push the two 75-kg cylinders up the incline. The force acts parallel to the plane and the coefficients of friction at the contacting surfaces are _A = 0.3, _B = 0.25, _C = 0.4. Each cylinder has a radius of 150 mm.

The 300-kg bar B, originally at rest, is being towed over a series of small rollers. Computer the force in the cable when t = 5s, if the motor M is drawing in the cable for a short time at a rate of v = (0.4t²) m/s, where t is in seconds (0 t 6 s). How far does the bar move in 5 s? Neglect the mass of the cable, pulley P, and the rollers.

The ball joint is subjected to the three forces shown. Find the magnitude of the resultant force.

Determine the magnitude of the resultant force by adding the rectangular components of the three forces.

The crane provides a long-reach capacity by using the telescopic boom segment DE. The entire boom is supported by a pin at A and by the telescopic hydraulic cylinder BC, which can be considered as a two-force member. The rated load capacity of the crane is measured by a maximum force developed in the hydraulic cylinder. If this maximum force is developed when the boom supports a mass m = 6 Mg and its length is l = 40 and = 60 , determine the greatest mass that can be supported when the boom length is extended to l = 50 m and = 45 . Neglect the weight of the boom and the size of the pulley at E. Assume the crane does not overturn. Note: when = 60 BC is vertical; however, when = 45 this is not the case.

A crane is constructed from two side trusses. If a load of 4 kN is suspended from one of these trusses as shown, determine the force in members FG, GK, and <KJ. State whether the members are in tension or compression. Assume the joints are pin-connected.

Determine the magnitude and direction of the couple shown.

The block B is suspended from a cable that is attached to the block at E, wraps around three pulleys, and is tied to the back of a truck. If the truck starts from rest when x_D is zero, and moves forward with a constant acceleration of a_D = 2 m/s², determine the speed of the block at the instant x_D = 3 m.

A truck T has a weight of 8,000 lb and is traveling along a portion of a road defined by the lemniscate r² = 0.2(106) cos 2 , where r is measured in feet and is in radians. If the truck maintains a constant speed of vr = 4 ft/s, determine the magnitude of the resultant frictional force which must be exerted by all the wheels to maintain the motion when = 0.

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 twist of 4 N-m is applied to the handle of the screwdriver. Resolve this couple moment into a pair of couple forces F exerted on the handle.

A uniform beam has a mass of 18 kg and rests on two surfaces at points A and B. Determine the maximum distance x to which the girl can slowly walk up the beam before it begins to slip. The girl has a mass of 50 kg and walks up the beam with a constant velocity.

A "scale" is constructed with a 4-ft-long cord and the 10-lb block D. The cord is fixed to a pin at A and passes over two small pulleys at B and C. Determine the weight of the suspended block E if the system is in equilibrium when s = 1.5 ft.

If the boom in the previous problem is to remain horizontal when the stone S is removed, what is x?

The composite cross section for the column consists of two cover plates riveted to two channels. Determine the radius of gyration k with respect to the centroidal axis. Each channel has a cross-sectional area of A_c = 11.8 in.² and moment of inertia (I )_c = 349 in.⁴.

If the hoist H is moving upward at 6 ft/s, determine the speed at which the motor M must draw in the supporting cable.

Determine the force F needed to hold the 4-kg lamp in the position shown.

Determine the force in each strut and tell whether it is in tension or compression.

A continuous of total length 4 m is wrapped around the small frictionless pulleys at A, B, C, and D. If the stiffness of each spring is k = 500 N/m and each spring is stretched 300 mm, determine the mass m of each block. Neglect the weight of the pulleys and cords. The springs are unstretched when d = 2 m.

The joint O of a space frame is subjected to four forces. Strut OA lies in the x-y plane and strut OB lies in the y-z plane. Determine the force acting in each if the three struts required for equilibrium of the joint. Set = 45 .

Determine the magnitudes ofthe forces P, R, and F required for equillibrium of point O.

Determine the tension developed in cables OD and OB and the strut OC, required to support the 500-lb crate. The spring OA has an unstretched length of 0.2 ft and a stiffness of k_OA = 350lb/ft. The force in the strut acts along the axis of the strut.

Cable BC exerts a force of F = 28 N on the top of the flagpole. Determine the projection of this force along the positive z axis of the pole.

Express force F as a Cartesian vector; then determine its direction angles.

Determine the magnitude of the x and y components of the 2 kN force.

The ends of the three cables are attached to ring at A and to the edge of a uniform 150-kg plate. Determine the tension in each of the cables for equilibrium.