Inertia Forces in Reciprocating Parts topics include: Kliens, bennetts and ritterhaus construction, velocity and acceleration of engines, reciprocating parts of engines. Inertia forces in reciprocating parts are caused by the oscillation of reciprocating masses. These forces act along the line of stroke and through the cross head on the structures and on the main bearing of the crankshaft.  The inertia force due to the acceleration of the reciprocating parts opposes the force on the piston. The inertia force due to retardation of the reciprocating parts helps the force on the piston.  The... Show more

Inertia Forces in Reciprocating Parts topics include: Kliens, bennetts and ritterhaus construction, velocity and acceleration of engines, reciprocating parts of engines.

Inertia forces in reciprocating parts are caused by the oscillation of reciprocating masses. These forces act along the line of stroke and through the cross head on the structures and on the main bearing of the crankshaft. 

The inertia force due to the acceleration of the reciprocating parts opposes the force on the piston. The inertia force due to retardation of the reciprocating parts helps the force on the piston. 
The inertial force of mass can be calculated by multiplying the object's mass by its acceleration. 
Balancing is a method of correcting or eliminating unwanted inertia forces and couples in rotating and reciprocating parts of the machine.

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Machine Dynamics Practice Test: Inertia Forces in Reciprocating Parts

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25 Questions

1. A Piston will remain in equilibrium if ________

Inertia force is applied in the direction Parallel to the resultant forceInertia force is applied in the same direction to the resultant forceInertia force is applied in the direction opposite to the resultant forceInertia force is applied in the direction Perpendicular to the resultant force

2. In a horizontal engine, reciprocating parts are retarded when the piston moves from _________

Midway to TDCTDC to BDCBDC to TDCBDC to midway

3. In the presence of frictional resistance, the expression for piston effort is _________

F(L) ± F(I) – R(f)F(L) + F(I)F(L) – F(I) + R(f)F(L) – F(I)

4. In which of the following cases Klein’s construction can be used?

Lever has a uniform angular accelerationCrank has a uniform angular accelerationWhen the motion is SHMCrank has a uniform angular velocity

5. The net force acting on the crosshead pin is known as __________

Shaft effortCrank effortPiston effortCrank pin effort

6. Why the inertia torque acts in the opposite direction to the accelerating couple?

Acts as a constraint torqueIncrease the linear accelerationBring the body in equilibriumTo reduce the accelerating torque

7. Which of the following expression represent the angular acceleration α of the connecting rod?

−ω2 . sin θ/nω2 . sin θ.nω2. cos θ/n−ω2 . cos θ.n

8. From the data given:
The length of the crank and connecting rod are 150 mm and 600 mm
The crank position is 60° from inner dead centre. The crank shaft speed is 400 r.p.m.
Find the angular acceleration in rad/s² of the connecting rod.

421388379400

9. When the piston is accelerated, the piston effort is given by which of the following the equation?

F(L) – F(I) + R(f)F(L) ± F(I)F(L) – F(I)F(L) + F(I)

10. From figure, acceleration of P with respect to C is given by_________

ω2.PCω2.CNω2.QNω2.OM

11. From the data given:
Crank and connecting rod of a steam engine are 0.3 m and 1.5 m in length; The crank rotates at 150 r.p.m. clockwise.
Determine the acceleration in m/s² of the piston for the same position(angle 40 degrees from IDC).

50.4159.2765.355.25

12. When the acceleration of the piston is 0, then the velocity is _____

MaximumHalf the maximumNegativeMinimum

13. In the given figure, the velocity of piston is maximum under which of the following conditions?

N lies to the right of ON lies above ON lies to the left of ON coincides with O

14. From figure, what is the velocity of P with respect to C?

ω × QNω × OCω × OMω × CM

15. For the given data of an Internal combustion engine : Mass of parts = 180 kg bore = 175 mm, length of stroke = 200 mm, engine speed = 500 r.p.m., length of connecting rod = 400 mm and crank angle = 60° from T.D.C, find the inertia force.

18.53 N17.56 N18.00 N19.2 N

16. In the expression F – m.a = 0, the term – m.a is called _______

Coriolis forceResultant forceReversed effective forceNet force

17. Bennett’ construction is used when the motion of the crank is linear cycloidal.

MaybeTrueFalseDon't Know

18. From the data given:
The length of the crank and connecting rod are 150 mm and 600 mm
The crank position is 60° from inner dead centre. The crank shaft speed is 400 r.p.m.
Find the acceleration in m/s² of the slider.

100.698.697.6101.5

19. Klein’s construction gives a graphical construction of a 4 bar chain.

TrueDon't KnowFalseMaybe

20. In given figure, Triangle OCM is known as ________

Klein’s acceleration diagramKlein’s displacement diagramBennet’s diagramKlein’s velocity diagram

21. From the data given:
crank-pin circle radius = 300mm
mass of the reciprocating parts = 250kg
difference between the driving and the back pressures is 0.45 N/mm²
The connecting rod length between centres is 1.2 m and the cylinder bore is 0.5 m.
engine runs at 250 r.p.m & 30° from T.D.C.
Find the piston effort.

37.3 kN35.2 kN32.4 kN40.2 N

22. Velocity of any point D on the connecting rod is given by ________

ω.ODω.PDω.OD1ω.OD2

23. In which of the following cases Bennett’s construction can be used?

When the motion is SHMLever has a uniform angular accelerationCrank has a uniform angular accelerationCrank has a uniform angular velocity

24. While calculating angular acceleration of the connecting rod, sin²(θ) term is neglected.

TrueFalseMaybeDon't Know

25. Which of the following is incorrect regarding inertia force?

Acts upon a rigid bodyBrings the body to equilibriumSame direction as of accelerating forceImaginary force