How does metro rail get power while running?

 

Metro rail systems typically get power while running through one of two methods: third rail or overhead wires (catenary system).

Third Rail

This method involves an additional rail, placed alongside the running rails, which supplies electric power. The train has a contact shoe that slides along this third rail, picking up the electricity needed to operate. This method is common in many urban metro systems because it is less visually intrusive and can be safer in terms of minimizing power lines overhead.

Overhead Wires (Catenary System)

In this method, the train draws power from overhead electrical wires using a pantograph, which is a device mounted on the roof of the train. This system is often used in light rail and tram systems, as well as some metro systems. It's particularly useful for above-ground sections of railways.

Both methods convert the supplied electricity into mechanical energy, which powers the train's motors and allows it to move.

Why Can't We See Dark Matter?

 

Imagine you're in a room with all the lights turned off – that's kind of what it's like trying to see dark matter. You can't see it directly because it doesn't give off any light or other types of radiation that our eyes or telescopes can detect. It's like a ghost that's there, but you can't see or touch it.

But just because we can't see dark matter doesn't mean it's not there. We know it exists because we can see its effects on the things around it. It's like knowing there's a hidden hand pushing things around in the dark – we can't see the hand, but we can see the objects moving because of it.

Dark matter mainly interacts with the universe through gravity, so it influences the way galaxies spin and how they're arranged in space. It's like a cosmic puppeteer, quietly shaping the universe from behind the scenes.

Even though we can't see dark matter directly, understanding its role in the cosmos is crucial for piecing together the puzzle of how our universe works. So, while it may remain invisible to our eyes, its presence is felt in every corner of the cosmos.

Why Are Solar Flares Hitting More Frequently Now?

Solar flares are happening more often now because the Sun is nearing the peak of its 11-year cycle, known as the solar maximum. During this time, the Sun's magnetic field is more active, causing more sunspots and magnetic storms on its surface. This activity leads to more frequent solar flares.

Solar flares are bursts of energy released from the Sun’s atmosphere, and when the Sun is more active, we see more of these bursts. This can affect things like satellite communications, power grids, and even create stunning auroras in the sky.

So, the reason we’re seeing more solar flares is simply because the Sun is in a more active phase of its natural cycle.

What is an exercise bike?

An exercise bike is a stationary bicycle which is used as exercise equipment for indoor cycling. It is usually a special-purpose exercise machine resembling a bicycle which has a saddle, pedals, and some form of handlebars but it doesn’t have any wheels.

Exercise bikes uses:

• increase general fitness,
• weight loss,
• training for cycle events.
• physical therapy

Best Exercise bikes for home provide low-impact, safe, and effective cardiovascular exercise. Operating the best stationary bike for home does not put much stress on joints and do not involve sporadic motions that some other fitness equipment may require.

Our top picks for The 7 best Exercise Bikes:

• Marcy Magnetic Recumbent Bike
• Sunny Health & Fitness Endurance Magnetic Belt Drive Indoor Cycling Exercise Bike
• Bluefin Fitness TOUR 5.0 Exercise Bike
• CIRCUIT FITNESS Circuit Fitness Magnetic Upright Exercise Bike
• SCHWINN Upright Series Bike
• Body Rider BCY6000
• 3G Cardio Elite UB Upright Bike

We discuss about the 7 best exercise bikes of 2021 based on their performance. We have selected one product from the 7 best exercise bikes based on our rating which you will get here: best exercise bikes.

What is an air fryer?

An air fryer is a small countertop convection oven designed to simulate deep frying without submerging the food in oil.

A fan is used to circulate hot air at high speed which produces a crisp layer via browning reactions such as the Maillard reaction.

How does an Air Fryer work?

An Air fryer uses a fan  to circulate hot air to cook food that would otherwise be submerged in oil. Heat from a heating element is radiated from air fryer’s cooking chamber near the food. The highest temperatures is 250 °C (482 °F) depending on the model.

Traditional frying methods completely submerge foods in hot oil inducing the Maillard effect at temperatures of between 140 to 165 °C (284 to 329 °F) which is well above the boiling point of water. In air fryer, a thin layer of oil is coated around the desired food and circulating air is heated up to 200 °C (392 °F) to apply heat and initiate the reaction. Therefore, the Air Fryer is able to brown foods like potato chips, chicken, fish, steak, cheeseburgers, french fries or pastries.

Why Air Fryer is a better option? 

• Cooking oil (70% to 80% less oil) is not used in large quantities in an air fryer which makes the Air fryer healthy for people.
• reduction of cooking times by 20% or more in the air fryer.
• air fryers are generally smaller and give off less heat.

The 10 best Air Fryers:

• Whynter Air Fryer
• TaoTronics Air Fryer
• Ninja Air Fryer
• COSORI Air Fryer
• Paula Deen Air Fryer
• Instant Pot air fryer
• Chefman air fryer
• GoWISE Air Fryer
• KUPPET Air Fryer
• Cuisinart Air Fryer

We discuss about the 10 best Air Fryers of 2021 based on their performance. We have selected one product from the 10 best Air Fryers based on our rating which you will get in our Best Air Fryers  reviews section in this link: the 10 best air fryers of 2021.

Why does object look larger in water relative to air?

In physics, refraction is normally the change in the path of a wave moving from one medium to a different or from a progressive change in the medium. Refraction of light may be the most commonly observed trend, but other waves for example sound waves and water waves also experience refraction. Just how much the wave is generally refracted is dependent upon the actual shift in wave speed and also the preliminary path associated with wave propagation relative to the path associated with alter in speed.

Light refraction follows Snell's law, which says that, for a given set of media, the ratio of the sines of the angle of incidence θ1 as well as angle of refraction θ2 is equivalent to the ratio of phase velocities (v1 / v2) in both media, or, the ratio of the indices of refraction (n2 / n1) of the two media. The refractive index or index of refraction of the material is a dimensionless quantity in optics that describes how fast light propagates within the material. The index of refraction indicates just how much the path of light is bent, or refracted, whenever entering a material.

Since air possesses a refractive index of essentially 1 and water comes with an index of refraction of just 1.33 the angle that the rays of light reach your eyes is bigger than the angle they might in air. This causes the angular size much larger for your eyes which makes the item appears larger compared to that they would likely appear in the air.

What is Nanotechnology?

Nanoscience and nanotechnology are the review and use of extremely small things and can be used across other science fields, such as chemistry, biology, physics, materials science, and engineering. Nanotechnology is taken as the scale range 1 to 100 nm following the definition used by the National Nanotechnology Initiative in the US. One nanometer (nm) is one billionth, or 10−9, of a meter. Nanotechnology is the adjustment and production of materials and devices on the scale of atoms or small groups of atoms. Nanotechnology makes it possible to manufacture lighter, more robust, and programmable materials that require less energy to produce than conventional materials, that produce less waste than with conventional manufacturing, and that promise greater fuel efficiency in land transportation, ships, aircraft, and space vehicles. Nanotechnology may be able to make current medical applications less expensive and a lot easier to use in places like the general practitioner's office and at home. Researchers at the University of Toronto have demonstrated the use of nanoparticles designed to concentrate on a tumor and generate oxygen can increase the efficiency of the chemotherapy drug doxorubicin. Researchers have successfully used DNA origami-based nanobots capable of carrying out logic functions to achieve specific drug delivery in cockroaches. Cars are being manufactured with nanomaterials so they may need fewer metals and less fuel to function in the future. Scientists are now turning to nanotechnology in an attempt to develop diesel engines with cleaner exhaust gases. Nanotechnology also has a prominent role in the fast developing field of Tissue Engineering. Scientists currently debate the future implications of nanotechnology. Nanotechnology may be able to develop many new materials and devices with a vast range of applications, such as in nanomedicine, nanoelectronics, biomaterials energy production, and consumer products. On the other hand, nanotechnology raises many of the same issues as any new technology, including issues about the toxicity and environmental effect of nanomaterials and their potential issues on global economics, as well as questions about various doomsday scenarios. These concerns have led to a controversy among advocacy groups and governments on whether special rules of nanotechnology is called for.