Grasp It

Introduction to Object Oriented Programming SHORT SUMMARY 1. Some of the quality issues of software such as correctness, usefulness, robustness, maintainability, reusability, portability, reliability and interoperability of the software must be kept in mind while developing software. 2. A programming paradigm describes the structure of a program. In other words, it determines how the instructions are placed in a program. Each programming language follows one or the other programming paradigm. 3. In unstructured programming paradigm, all the instructions of a program were written one after the other in a single function and hence was suitable for writing only small and simple programs. 4. In procedural programming, programs are divided into different procedures (also known as functions, routines or subroutines) and each procedure contains a set of instructions that performs a specific task. It follows a top-down approach. 5. Programs in procedural programming consist ...

How do you stop a speeding car? This is how a police chase the fugitive 1  Speeding car High-speed chases can last hours and are very dangerous, so officers use the precision immobilization technique (PIT) to stop the fugitive’s car. 2  In pursuit The police officer begins the maneuver by aligning the front of their car with the back of the car being chased. 3  Losing traction The rear wheels lose grip against the road, sending the suspect’s car into a skid. 4  Sharp turn The pursuing officer then steers their car sharply into the side of the fugitive’s vehicle, making them spin. 5  End of the road The fugitive either lets the car spin out of control or resorts to braking, ending the chase either way. 6  Keep turning The officer continues to turn in the same direction until they are clear of the car, preventing the criminal from correcting the skid.

How do you balance on a unicycle? Get a handle on the forces that keep you upright on one wheel T o balance on a unicycle, you have to keep pedaling. It’s Newton’s first law: an object in motion tends to stay in motion. Maintaining stability, however, is the hard part. Three forces are at work here: gravity, contact, and friction.  Gravity pulls the unicycle down and contact force with the ground pushes back. The surface that the unicycle is moving along exerts friction, which is what allows the unicycle to balance, speed up and slow down. The rider has to keep accurate posture, in alignment with the frame of the unicycle. As soon as he begins to tip, he will fall as he is in unstable equilibrium. However, he needs to tilt his body to move. In order to go forward, the unicyclist leans forward. This means changing the point of contact to maintain the center of gravity, which means constant pedaling. He also has to countersteer to turn. This means moving in the opposite dir...

What makes up a road? The construction process is more complex than you might think I t is believed that the first roads paved with bricks were created in the Indus Valley more than 5,000 years ago. Today, there are plenty of roads on Earth to circle the planet over 600 times, but bricks are no longer the material of preference when constructing new roads. In fact, the roads of today are built using layers of many different materials. Vehicles are heavy – a typical family car weighs well over a ton – which indicates that roads have to be tough enough to withstand the pressures involved. That’s why the load is spread over four layers. At the bottom is the sub-grade – this is the local soil that is compressed with a roller. Next, you have the sub-base, typically made from crushed concrete. The base comes next – another layer of finely crushed rock mixed with asphalt and slag, which is a waste product from steel production. Then comes the smelly stuff – the binder and surface...

What is the best way to beat jet lag? C ontrolling your light exposure and  melatonin levels, ideally before you travel is the most efficient way of overcoming jet lag. These cues control your circadian rhythm, an internal clock that governs sleep, hunger and other cycles – and makes you to feel jetlagged when you switch time zones. A few days before traveling, use a bright light to simulate the time of day at your destination. This will help you adjust to the change in time zones more easily. When it’s early evening there, take melatonin, a hormone released naturally by your body to cause drowsiness and urge you to sleep.

What is the future of VTOL aircraft? T he enormous cargo vessels that travel the world on enormous ships are currently moved onto large trucks when they arrive the port, and directed to their final destination by road. However, British company Reinhardt Technology Research (RTR) believes it would ultimately be quicker, cheaper, and more environmentally friendly to fly them alternatively. The company has recently designed the TU 523, a vertical take-off and landing (VTOL) aircraft that is proficient of transporting heavy shipping containers without the need for expensive new infrastructure. The craft uses a hybrid electric generator to provide power to a series of electric turbines on demand, which can tilt horizontally and enable vertical take-off and landing. Once in the air, the turbines turn back again, while the wings generate lift just like on an airplane. RTR has already built a 1:4 scaled model of the TU 523. It will then produce a full-scale ...

How do we fire torpedoes? T orpedoes can be launched from both ships and submarines during warfare, using torpedo tubes placed up along the hull. World War II-era torpedoes were guided towards the destination using an internal gyroscope, and their pathway could be fine-tuned using the rudders after they had been released. A pendulum inside of the torpedo kept it level after its release. Many modern torpedoes are wire guided, which means that they can be commanded remotely after their launch, before the wire is cut off and the internal supervision system takes over. Once the torpedo detects an enemy the ship, or makes contact with it, the on-board explosive is detonated to rip a hole in its side in order to send it settling to the bottom of the ocean without a proof.

How do we fill tyres with nitrogen? W hile we typically fill our car tyres with normal air, Formula 1 teams and even airlines fill their vehicles’ tyres with purified nitrogen. They do this to boost performance and reliability, so should we be doing the same? The air you pump into your tyres is actually mostly nitrogen anyway – 78 % of it to be exact – but it’s the other 22 % that is the problem. Less than one percent is water vapour, which at very low temperatures, such as those at high altitudes, and very high temperatures, such as those produced when driving very fast can freeze or expand to make the tyre pressure unstable. For normal driving though, this shouldn’t be a problem, so dryer nitrogen won’t make much difference. However, air is also 21 percent oxygen, and as oxygen molecules are so tiny, they drip through the tyre rubber over time. Nitrogen molecules on the other hand, are bigger, so they stay inside the rubber for longer ...

Ocean pollution From oil and debris to sewage and toxic chemicals – our seas have it all O ceans cover 71 % of our planet’s surface and contain an estimated 1.5 million species, but that hasn’t stopped humanity using the sea as a giant, watery rubbish bin. We’re familiar with terrible images of seabirds whose feathers are clogged with viscous black oil. But catastrophic spills from tankers account for just a portion of oil pollution in the sea; street runoff, vehicle exhausts, and industrial waste are all chronic contributors to the problem. Indeed, almost all marine pollution stems from activities on land. Runoff from farms introduces pesticides and insecticides into the aquatic food chain, as well as an overabundance of nutrients in the form of fertilizer. This causes populations of algae to spike, draining the surrounding waters of oxygen and choking other marine life. Finally, human-made rubbish is everywhere throughout the world’s oceans, where it is corralled by currents i...