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What do you need to do to prevent a raw egg from sinking on the bottom of a glass with water?
It's all about water density. Since an egg has a higher density than pure water, it sinks when put into a glass. However, salted water has a higher density than an egg, which makes an egg float close to the surface.
Heat the water
Put a magnet close to the glass
Add some salt to the water
Say a spell
You're holding a lit match 10-15 cm from the wall. Then you light a flashlight at the match. What is it that you won't see on the wall?
Fire doesn't throw a shadow because the light comes through the flame freely, without meeting any obstacles.
Shadow of your hand
Shadow of the match
Shadow of the flame
The wall itself
A mirror lies on the bottom of a bowl filled with water. You light a flashlight at the mirror and catch the reflected light on a piece of paper. What will you see on the paper?
When coming through water, a ray splits into separate colors. It looks like a rainbow.
Bowl
Fold
Rainbow
Secret messages
A wet coin lies on the neck of an open empty bottle. How do you make the coin jump into the air?
When you put the bottle into the freezer, the air inside it compresses. Once you take the bottle outside, the air warms up and starts to expand, pushing the coin up.
Say a spell
The coin must be made of pure gold
Magnetize the coin
Put the bottle into the freezer
In summer, it's 300 meters longer than in winter. What is it?
In summer, the length of a railway track is bigger than in winter. Each additional degree of Celsius makes a railway track 0,00001 longer. Suppose, the difference between the summer and winter temperatures is 55°. By multiplying the length of the track (640 km) by 0,00001 and then by 55, we get 1/3 km. Thus, in the summer, the railway track between Moscow and St. Petersburg is about 300 meters longer than in winter.
Moscow-St.Petersburg railway
Coastal line of Black sea
The tallest tree
Ostankinskaya Tower
For a better understanding of the studied subject, a physician Vasiliy Petrov had to remove the upper layer of epithelium on the tips of his finger. Which physical phenomenon did he study?
In 1802, a Russian scientist Vasiliy Petrov discovered the phenomenon of electric arc. Petrov did a series of experiments involving electric current. Since there were no amperemeters or voltage meters back in 1802, the scientist had to measure the electric current and battery operation by relying on his senses. To be able to feel low-voltage currents, Petrov had to take off the upper layer of skin on the tips of his fingers.
X radiation
Electric arc
Refraction of light in glass prism
Reactive motion
Which object has the highest temperature?
The temperature of Earth's core is about 6,000 C. The temperature of volcanic lava varies between 500 and 700 C. The temperature of Sun varies from 6,000 C on the surface to 10,000,000 C in the core. The temperature of a lighting is about 25,000 C.
Earth's core
Lighting
Sun surface
Volcanic lava
In the universe, there are about 3,500 of these objects.
Planet Proxima b is the closest Earth-like planet to Earth. It is located 4,2 light years (about 40 trillion km) away from us. You can see it below in the picture made by Hubble telescope.
Comets
Asteroids
Galaxies
Earth-like planets
What was the first object to break the sound barrier?
Yes, it's an ordinary whip which is used to make the cattle behave. The end of a whip is moving very fast, creating a shock wave in the air. A supersonic jet uses the same mechanism.
Whip
Wheel
Pendulum
Bow
In 1746, a French physician and priest Jean Antoine Nollet studied the speed of this physical phenomenon. In one of his experiments, the scientist tied up 200 monks with iron wires. What did he want to measure?
Nollet's goal was to measure the speed of electric current. All over the monks, he hung Leyden jars, which were the prototypes of modern condensers . All the monks responded to the impact simultaneously, which proved that the speed of electricity was very high.
Speed of electric current
Durability of spring
First space speed
Planck's constant
Low pressure areas are an integral part of this sports competition. Once, it even caused a fire that put a stop to an event. Which sport is it?
Race cars are moving at such a high speed that it creates a low pressure area between a car bottom and road surface. The pressure is high enough to open a hatch door. This is exactly what happened at a race once. A car's hatch door crashed into the nearest car. There was a fire and the race had to be stopped. Since then, hatch doors are welded to the frame.
Cycling
Biathlon
Tennis
Formula 1
Aspiring physician
We hate to break it to you but your knowledge leave much to be desired.... You can't count on a degree in physics just yet. On the brighter side, now you know how to make an egg float in a glass of water, why one physician took off skin off his fingers, and another scientist made expriments on people. Share this quiz with your friends to find out which one of you knows physics best!
Physics fan
Wow! We're impressed. You have a pretty solid knowledge of physics. Have you ever thought about picking physics as a career? You should consider this option. You know how to make an egg float in a glass of water, why one physician took off skin off his fingers, and another scientist made expriments on people. Share this quiz with your friends to find out which one of you knows physics best!
Professor
You seem to know the laws of physics like the back of your hand. You've read plenty of books and watched multiple documentaries on physical phenomena and famous scientists. You know how to make an egg float in a glass of water, why one physician took off skin off his fingers, and another scientist made expriments on people. Share this quiz with your friends to find out which one of you knows physics best!
