Theory of Machines 14th. Edition by R.S. Khurmi, J.K. Gupta | 9788121925242 | 812192524X | Holooly

Theory of Machines

Theory of Machines [EXP-6571]

391 SOLVED PROBLEMS

A 150 mm diameter valve, against which a steam pressure of 2 MN/m^2 is acting, is closed by means of a square threaded screw 50 mm in external diameter with 6 mm pitch.If the coefficient of friction is 0.12 ; find the torque required to turn the handle.

Verified Answer:

Given : D = 150 mm = 0.15 mm = 0.15 m ; [latex...

A 60 mm diameter shaft running in a bearing carries a load of 2000 N. If the coefficient of friction between the shaft and bearing is 0.03, find the power transmitted when it runs at 1440 r.p.m.

Verified Answer:

Given : d = 60 mm or r = 30 mm = 0.03 m ; W =...

A band and block brake, having 14 blocks each of which subtends an angle of 15° at the centre, is applied to a drum of 1 m effective diameter. The drum and flywheel mounted on the same shaft has a mass of 2000 kg and a combined radius of gyration of 500 mm. The two ends of the band are attached to

Verified Answer:

Given : n = 14 ;

2 \theta=15^{\circ} \text ...

A band brake acts on the 3/4th of circumference of a drum of 450 mm diameter which is keyed to the shaft. The band brake provides a braking torque of 225 N-m. One end of the band is attached to a fulcrum pin of the lever and the other end to a pin 100 mm from the fulcrum. If the operating force is

Verified Answer:

Given : d = 450 mm or r = 225 mm = 0.225 m ; [late...

A belt drive consists of two V-belts in parallel, on grooved pulleys of the same size. The angle of the groove is 30°. The cross-sectional area of each belt is 750 mm^2 and m. = 0.12. The density of the belt material is 1.2 Mg/m^3 and the maximum safe stress in the material is 7 MPa. Calculate the

Verified Answer:

Given :

2 \beta=30^{\circ} \text { or } \...

A bicycle and rider of mass 100 kg are travelling at the rate of 16 km/h on a level road. A brake is applied to the rear wheel which is 0.9 m in diameter and this is the only resistance acting. How far will the bicycle travel and how many turns will it make before it comes to rest ? The pressure

Verified Answer:

Given : m = 100 kg, v = 16 km / h = 4.44 m / s ; D...

A body of mass 20 kg is suspended from a spring which deflects 15 mm under this load. Calculate the frequency of free vibrations and verify that a viscous damping force amounting to approximately 1000 N at a speed of 1 m/s is just-sufficient to make the motion aperiodic. If when damped to this

Verified Answer:

Given : m = 20 kg ;

\delta=15 mm =0.015 m[/...

A body, resting on a rough horizontal plane required a pull of 180 N inclined at 30º to the plane just to move it. It was found that a push of 220 N inclined at 30º to the plane just moved the body. Determine the weight of the body and the coefficient of friction.

Verified Answer:

Given :

\theta=30^{\circ}

Let ...

A braking system has its braking lever inclined at an angle of 30° to the horizontal plane, as shown in Fig. 19.7. The mass and diameter of the brake drum are 218 kg and 0.54 m respectively. At the instant the lever is pressed on the brake drum with a vertical force of 600 N, the drum is found to

Verified Answer:

Given : m = 218 kg ; d = 0.54 m or r = 0.27 m ; P ...

A cam consists of a circular disc of diameter 75 mm with its centre displaced 25 mm from the camshaft axis. The follower has a flat surface (horizontal) in contact with the cam and the line of action of the follower is vertical and passes through the shaft axis as shown in Fig. 20.50. The mass of

Verified Answer:

Given : d = 75 mm or r = OA = 37.5 mm ; OQ = 25 mm...

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