Physics
What is the name of the phenomenon where light bends as it passes from one medium to another?
Refraction
What is the name of the type of chemical reaction where a substance reacts with oxygen to produce heat and light?
Combustion reaction
What is the name of the point on a stress-strain curve where the material starts to deform permanently?
Yield point
What is the pigment that makes plants green?
Chlorophyll
Argentina
Explain the Bernoulli's principle of fluid flow
An increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy
What are the two main components of a buffer solution?
A weak acid and its conjugate base, or a weak base and its conjugate acid
What is the difference between accuracy and precision?
Accuracy: closeness to the true value. Precision: closeness of measurements to each other
This pioneering female scientist discovered two radioactive elements, polonium and radium. She was the first woman to win a Nobel Prize and remains the only person to have won Nobel Prizes in two different scientific fields. Who is she?
Marie Curie
How many Ballon d'Or awards (Golden Ball) did Lionel Messi win in his career?
8
How many electrons are needed to form a charge of −0.3 nC? The elementary charge is e = 1.6⋅10^(−19) C
1875000000
When a copper coin is dropped into a beaker containing concentrated nitric acid, almost immediately, the solution starts turning blue, and a reddish-brown gas is released. Finish and balance the chemical equation for this reaction:
Cu+HNO3=?
Cu+4HNO3=Cu(NO3)2+2NO2+2H2O
A professional soccer field (7140 m²) receives a heavy rainfall of 12 mm. The water distribution occurs as follows: 50% infiltrates into the soil.
20% evaporates due to wind and heat.
10% is absorbed by the grass and retained.
The remaining water flows into the field drainage system. What should be the drainage system capacity to prevent flooding?
Total rainfall = Rainfall Depth*Field Area*time=0.012×7140=85,680 L
Infiltration: 0.50×85,680=42,840L
Evaporation: 0.20×85,680=17,136 L
Absorption by Grass: 0.10×85,680=8,568 L
Runoff for Drainage: Drainage Load=85,680−(42,840+17,136+8,568)=85,680−68,544 =17,136 L
Drainage capacity should be more than 17 136 L or 17.14 m^3
Some jellyfish (Turritopsis dohrnii) are biologically immortal. Why do humans age at all?
Humans age because telomeres—protective caps at the ends of chromosomes—shorten with each cell division. Over time, this shortening leads to cellular aging and dysfunction. Unlike humans, Turritopsis dohrnii can reverse its life cycle, restoring its cells to an earlier state, effectively bypassing aging.
In what year was the last time Astana won the Kazakhstan Cup?
2016
If a small asteroid enters Earth's atmosphere at high speed, why does it burn up before reaching the ground?
When a small meteor enters the Earth's atmosphere, it goes from travelling through a vacuum to travelling through air. Traveling through a vacuum is effortless and the velocity might reach tens of thousands of kilometers per hour. When the meteor hits the atmosphere, the air in front of it compresses incredibly quickly. When a gas is compressed, its temperature rises. This causes the meteor to heat up so much that it glows.
A 2.5 g sample of calcium carbonate (CaCO₃) is completely decomposed by heat into calcium oxide and carbon dioxide. What is the volume of CO₂ gas produced at standard temperature and pressure (STP)?
A(Ca)=40.08 g/mol
A(C)=12.01 g/mol
A(O)=16.00 g/mol
0.560L
The traditional soccer ball is 32-paneled: it has 20 hexagons and 12 pentagons to approximate its shape to a sphere. But the modern designs have way less panels ranging from 6 to 14. What are the advantages of the modern design?
less panels->less air resistance->smoother and faster flight
This "thing", originally used by Native Americans as a natural resin from spruce trees, was later commercialized in 1848 by John B. Curtis, who created the first marketed version known as The State of Maine Pure Spruce " ". Chemically, it evolved from natural polymers to synthetic elastomers for improved texture and longevity. What is it?
Chewing gum
When is a green card given to a player?
A green card is a referee's badge in football, indicating that the player who received it follows the principles of fair play, is not shown, unlike yellow and red, but is noted in the match report.
A soccer ball is dropped from a height of 1.5 meters onto wet grass. If the coefficient of restitution (COR) between the ball and the wet ground is 0.4, what is the height of the ball’s first bounce? Ignore the air resistance
Hint: Use energy conservation and the formula for COR: e=Velocity after impact/Velocity before impact
0.24m
A 15.0 g sample of aluminum (Al) reacts with 40.0 g of oxygen gas (O₂) to form aluminum oxide (Al₂O₃) according to the balanced equation: 4Al+3O2=2Al2O3
A(Al)= 26.98 g/mol
A(O) = 16.00 g/mol
If the actual mass of Al₂O₃ produced is 25.0 g, calculate the percent yield
88.2%
A team is designing a tensile fabric roof for the soccer stadium, supported by steel cables. The roof has an area of 20,000 m² and total weight of 400 kg per square meter. Columns that can bear 2500 kN will be used to support the roof. Ignoring the wind speed and aerodynamic pressure, how many such columns are needed?
Total Load=Roof Area×Load per m²×9.81=20,000×400×9.81 =78,480 kN;
Number of Columns=Total Load / Load per Column=78,480 / 2,500 = 31.4
Since we can't have a fraction of a column, we round up to 32 columns.
Why does a wet road appear darker than a dry one, even though water itself is transparent?
Water reduces diffuse reflection by filling in tiny surface gaps, creating a smoother surface that allows more light to be refracted away instead of scattering toward your eyes. This makes the road appear darker.
In the 2014 FIFA World Cup, this German midfielder set a record for the most accurate passes in a single World Cup match. He also scored twice in the historic 7-1 semi-final win against Brazil. Known for his incredible vision and control, he has won league titles in two different countries and multiple Champions League trophies. Who is he?
Toni Kroos