Physics Form 4: Chapter 3 - Application of Bernoulli principle (WindSurfing)

 

• The air flow over the sail causes an increase in pressure on the windward side and a decrease on the leeward side
• Area of leeward side has a low pressure because of the high speed of the wind.
• A resultant force acts in the direction of F.
• This resultant force can be resolved into component to the right and left.
• The component to the right can be balanced by the surfer who pulls it to the left.
• Therefore, there exists a resultant force to the front so that the surfer moves to the front.
• Factors affect the resultant force is the strength of the wind and the shape of the sail. 

Mirror of Georgetown Heritage City

A cutting edge street art project by international artist Ernest Zacharevic, the project consists of six to 12 mural paintings created on the walls of buildings within the Georgetown heritage area. The paintings will depict figure drawings and portraits of various inhabitants of the city celebrating the multiculturalism and diversity of the town.

All photos above are courtesy of Ernest Zacharevic and Penang traveltips site

Ernest Zacharevic facebook page

 Penang Traveltips site

Physics Form 5: Chapter 3 - Application of Electromagnetic Induction (Torchlight)

Electromagnetic induction is the production of induced current by changing magnetic field. By using kinetic energy of shaking hand, electrical energy is produced to power the flash light through electromagnetic induction.

Kinetic energy ------> Electrical energy

• A powerful permanent magnet such as neodymium magnet is used because of small size with strong magnetic field. The permanent magnet is placed inside a plastic track which allow it to slide up and down.
• The shaking hands move the strong magnet to cut through the copper coils causing electromagnetic induction. 
• The electrical energy produced is stored in a capacitor that can be charged hundreds of thousands times.
• The bulb is an energy efficient ultra bright white LED that can produce a beam of light for several minutes after shaking the moving magnet for 30 seconds.

For more information, click below video

How She Passed the Driving Licence?

Physics Form 5: Chapter 3 - Application of Electromagnet (Telephone Earpiece)

When you listen to your telephone, the receiver in the earpiece reverses the electrical signals from the telephone wire back into sound that we can hear.

How does a telephone earpiece work?

Click on the diagram below to play!

No Malaysian in Harvard U.

KUALA LUMPUR, April 7 — Malaysians failed to gain admission into the world’s most prestigious university for the second year in a row due to a slide in the quality of applicants, said Harvard University’s selection panel chief for Malaysia.


Not only did no Malaysian student receive an offer letter but none apparently was even good enough to make it to the interview rounds. This comes after a controversy erupted over the quality of Malaysian education when Education Minister Tan Sri Muhyiddin Yassin pointed to a World Economic Forum report to claim that Malaysians had a higher standard of education compared to that in some advanced countries.


Datuk Dr Goh Cheng Teik, who leads the Harvard team that interviews prospective Malaysian students, said he was informed the quality of applicants had deteriorated.

“I called the Harvard College of Admissions Office and was told that although they received applications from Malaysian students, no one was shortlisted for interviews as they are not considered competitive enough,” he was quoted as saying by The Star.

A two-year absence from incoming Harvard freshman classes is enough to raise concerns over the quality trends of Malaysian education given that at least one Malaysian had been admitted to Harvard every year from 1985 to 2010.

A statement from Harvard’s interview panel showed that Malaysia was only fourth among Southeast Asian countries in terms of enrolment in the Ivy League institution.

Singapore has the highest number of Harvard undergraduates with 18, followed by Thailand with seven, Vietnam with six, Malaysia with five and Indonesia with two.

It was ranked the No. 1 university in the world last year by the Center for World-Class Universities of Shanghai Jiao Tong University. Some 34,950 applicants were received by Harvard for the 2016 graduating class and only 6.3 per cent were accepted.

Higher number of straight A+ scorers in SPM 2011

PUTRAJAYA: A total of 559 (0.12%) of 468,808 students scored straight A+ in last year's Sijil Pelajaran Malaysia (SPM) examinations, compared with 403 (0.08%) straight A+ scorers in 2010.

Education director-general Datuk Seri Abdul Ghafar Mahmud said overall student achievement in the examinations has continually improved in the past four years.

He said 506 of the straight A+ candidates were from national secondary schools and 53 from other schools, compared with 363 and 40 respectively in 2010.

"The overall SPM achievement for 2011 improved from the year before, with the National Average Grade at 5.04 compared with 5.19 in 2010," he added.

"The overall achievement of schools also improved, as the number of schools in the 'excellent' and 'good' categories increased by 13 and 60 schools respectively," he said when announcing the SPM 2011 results analysis at the Education Ministry here Wednesday.

Abdul Ghafar said schools were gauged using the School Average Grade and categorised as "excellent", "good", "satisfactory", and "potential".

Physics Form 5: Chapter 1 - Application of Reflection of Sound

Echoes are caused by the reflection of sound. A sound wave will continue to bounce around or reverberate until it has lost all its energy. A wave has some of its energy absorbed by the objects it hits. The rest lost as heat energy.

The phenomenon of the reflection of sound is used to determine the distance between the two objects, for example depth of seabed, depth of cave or width of a valley. The type of sound used must be ultrasound.

Sonar (Sound Navigation and Ranging). Sonar is used to detect underwater objects (corals / fishes) or to determine the depth of the water by means of an echo. Sonar equipment emits a high frequency sound signal which is reflected by the object in the water. The reflected sound wave is received by the sonar receiver. The time taken for the echo to return is used to determine the distance of the object below the water surface. 

Sonar waves of high frequency is used because it possesses more energy, high penetration power and can travel further through water.

Click on the diagram below to play!