Wednesday 31 August 2016
micro metre screw gauge for 9-C
Its an effective and detailed video from the youtube.com
https://www.youtube.com/watch?v=11EM0nZUdqE
The URL is given above, click it to see the video.
Screw Gauge: (history)
The word micrometer is a neoclassical coinage from Greek micros, meaning "small", and metron, meaning "measure". The Merriam-Webster Collegiate Dictionary says that English got it from French and that its first known appearance in English writing was in 1670. Neither the metre nor the micrometre (μm) nor the micrometer (device) as we know them today existed at that time. However, the people of that time did have much need for, and interest in, the ability to measure small things and small differences. The word was no doubt coined in reference to this endeavor, even if it did not refer specifically to its present-day senses.
The first ever micrometric screw was invented by William Gascoigne in the 17th century, as an enhancement of the vernier; it was used in a telescope to measure angular distances between stars and the relative sizes of celestial objects.
Henry Maudslay built a bench micrometer in the early 19th century that was jocularly nicknamed "the Lord Chancellor" among his staff because it was the final judge on measurement accuracy and precision in the firm's work. In 1844 details of Whitworth's workshop micrometer were published. This was described as having a strong frame of cast iron, the opposite ends of which were two highly finished steel cylinders, which traversed longitudinally by action of screws. The ends of the cylinders where they met was of hemispherical shape. One screw was fitted with a wheel graduated to measure to the ten thousandth of an inch. His object was to furnish ordinary mechanics with an instrument which, while it afforded very accurate indications, was yet not very liable to be deranged by the rough handling of the workshop.
Thanks for your time
Yours Truly
Kashif Jamal
https://www.youtube.com/watch?v=11EM0nZUdqE
The URL is given above, click it to see the video.
Screw Gauge: (history)
The word micrometer is a neoclassical coinage from Greek micros, meaning "small", and metron, meaning "measure". The Merriam-Webster Collegiate Dictionary says that English got it from French and that its first known appearance in English writing was in 1670. Neither the metre nor the micrometre (μm) nor the micrometer (device) as we know them today existed at that time. However, the people of that time did have much need for, and interest in, the ability to measure small things and small differences. The word was no doubt coined in reference to this endeavor, even if it did not refer specifically to its present-day senses.
The first ever micrometric screw was invented by William Gascoigne in the 17th century, as an enhancement of the vernier; it was used in a telescope to measure angular distances between stars and the relative sizes of celestial objects.
Henry Maudslay built a bench micrometer in the early 19th century that was jocularly nicknamed "the Lord Chancellor" among his staff because it was the final judge on measurement accuracy and precision in the firm's work. In 1844 details of Whitworth's workshop micrometer were published. This was described as having a strong frame of cast iron, the opposite ends of which were two highly finished steel cylinders, which traversed longitudinally by action of screws. The ends of the cylinders where they met was of hemispherical shape. One screw was fitted with a wheel graduated to measure to the ten thousandth of an inch. His object was to furnish ordinary mechanics with an instrument which, while it afforded very accurate indications, was yet not very liable to be deranged by the rough handling of the workshop.
Thanks for your time
Yours Truly
Kashif Jamal
Tuesday 30 August 2016
refraction in waves according to the wavefront...
direction of wave motion is perpendicular to the wavefront
dont get mixed up with wavefront and direction of a wave :)
wave motion, video for 10C
here are two videos and i suggest you watch both, it will take hardly 5 minutes :)
https://youtu.be/nD0xR60xthg
https://youtu.be/QCNQs9Cgyfg
https://youtu.be/nD0xR60xthg
https://youtu.be/QCNQs9Cgyfg
Monday 29 August 2016
revision notes for waves for 10-C
check your own learning and assess yourselves that where do you stand in the row.
Saturday 27 August 2016
measurements and physical quantities formative assessment
Friday 26 August 2016
welcom
hi
you are welcomed to have a good exposure to physics 5054 throughout the session for your cie exams.
kashif jamal
you are welcomed to have a good exposure to physics 5054 throughout the session for your cie exams.
kashif jamal
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