- 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.
Sunday, July 22, 2012
Friday, July 6, 2012
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
Sunday, July 1, 2012
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