Machine Kinematics Questions and Answers – Centre of Percussion

1 The piston of a steam engine moves with simple harmonic motion. The crank rotates at 120 r.p.m. with a stroke of 2 metres. Find the velocity of the piston, when it is at a distance of 0.75 metre from the centre.

A 8 m/s

B 8.31 m/s

C 9 m/s

D none of the mentioned

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Answer: 8.31 m/s

2 The piston of a steam engine moves with simple harmonic motion. The crank rotates at 120 r.p.m. with a stroke of 2 metres. Find the acceleration of the piston, when it is at a distance of 0.75 metre from the centre.

A 118.46 m/s²

B 90 m/s²

C 100 m/s²

B none of the mentioned

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Answer: 118.46 m/s²

3 Law of isochronism

A states the time period (t_p ) of a simple pendulum does not depend upon the mass of the body suspended at the free end of the string.

B states the time period (t_p ) of a simple pendulum does not depend upon its amplitude of vibration and remains the same, provided the angular amplitude (θ) does not exceed 4°.

C states the time period (t_p) of a simple pendulum is directly proportional to √L , where L is the length of the string.

D none of the mentioned

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Answer: states the time period (t_p ) of a simple pendulum does not depend upon its amplitude of vibration and remains the same, provided the angular amplitude (θ) does not exceed 4°.

4 Law of mass

A states the time period (t_p ) of a simple pendulum does not depend upon the mass of the body suspended at the free end of the string.

B states the time period (t_p ) of a simple pendulum does not depend upon its amplitude of vibration and remains the same, provided the angular amplitude (θ) does not exceed 4°.

C states the time period (t_p ) of a simple pendulum is directly proportional to √L , where L is the length of the string.

D none of the mentioned

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Answer: states the time period (t_p ) of a simple pendulum does not depend upon the mass of the body suspended at the free end of the string.

5 Law of length

A states the time period (t_p ) of a simple pendulum does not depend upon the mass of the body suspended at the free end of the string.

B states the time period (t_p ) of a simple pendulum does not depend upon its amplitude of vibration and remains the same, provided the angular amplitude (θ) does not exceed 4°.

C states the time period (t_p) of a simple pendulum is directly proportional to √L , where L is the length of the string.

D none of the mentioned

View Answer

Answer: states the time period (t_p) of a simple pendulum is directly proportional to √L , where L is the length of the string.

6 Law of gravity

A states the time period (t_p ) of a simple pendulum does not depend upon the mass of the body suspended at the free end of the string.

B states the time period (t_p ) of a simple pendulum does not depend upon its amplitude of vibration and remains the same, provided the angular amplitude (θ) does not exceed 4°.

C states the time period (t_p) of a simple pendulum is directly proportional to √L , where L is the length of the string.

D states the time period (t_p ) of a simple pendulum is inversely proportional to √g , where g is the acceleration due to gravity.

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Answer: states the time period (t_p ) of a simple pendulum is inversely proportional to √g , where g is the acceleration due to gravity.

7 A helical spring, of negligible mass, and which is found to extend 0.25 mm under a mass of 1.5 kg, is made to support a mass of 60 kg. The spring and the mass system is displaced vertically through 12.5 mm and released. Determine the frequency of natural vibration of the system.

A 6 Hz

B 4.98 Hz

C 5.98 Hz

D none of the mentioned

View Answer

Answer: 4.98 Hz

8 A helical spring, of negligible mass, and which is found to extend 0.25 mm under a mass of 1.5 kg, is made to support a mass of 60 kg. The spring and the mass system is displaced vertically through 12.5 mm and released. Find the velocity of the mass, when it is 5 mm below its rest position.

A 0.36 m/s

B 0.46 m/s

B 0.56 m/s

B none of the mentioned

View Answer