Fact or Fiction | Laws of physics: we refute false statements using a scientific approach

A coin falling from a skyscraper will not only fail to reach "lethal" speed but will stop accelerating after two to three seconds of falling. Air resistance will balance the acceleration of free fall, and the coin will fall at a constant speed for almost the entire distance. Therefore, it does not matter from what height it is dropped: from 300 m or 3 km — the result will be the same. If all falling bodies in the atmosphere moved with acceleration, even ordinary rain would be deadly.

The common lightning rod, installed on every house, tower, factory chimney, or any other tall building, disproves this misconception. The higher the lightning rod is installed, the more often lightning strikes it.

Read more misconceptions about lightning in our article ☛

Liquids exert pressure in all directions, including upward. Otherwise, any object placed in water would instantly sink to the bottom, and swimming would be out of the question.

Cats don't get hurt because physics, not biology or physiology, is involved. As the height increases, the likelihood of a cat dying does not increase. This is because during the fall, cats spread their legs as wide as possible, thus increasing the area of their cross-section. In other words, the animal's body starts to work like a parachute, increasing resistance and reducing speed. The laws of mechanics and aerodynamics play a key role here.

Read more interesting facts about cats in our article ☛

In reality, without friction, all bodies would begin to move, striving to reach the lowest point. Brake pads, pulleys and belts, tires, and the road would not experience mutual friction, and therefore would not work. Our houses would collapse in an instant: mortar would no longer hold the bricks, as they are held in place only by friction.

Theoretically, on the Moon, a person can jump up to 2–3 m high, but only if done without a spacesuit and after extensive preparation. If you jump on the Moon with the same force as on Earth, there is a high likelihood of flying not upwards but forwards or backwards, while also acquiring rotational momentum.

Read more misconceptions about space in our article ☛

In some conditions, a voltage of 10–15 volts can become dangerous; and conversely, a current of 10,000 volts may cause no harm at all. It is necessary to take into account not only the voltage but also the current's amperage.

Any change in the amount of energy in a body inevitably leads to a change in its mass. So how much does the mass of a liter of water change when taken at room temperature and brought to a boil? Not much. However, a ton of water will produce a value at the edge of instrumental error: 1,000 kg of water brought to a boil will weigh just 0.000005 g more.

By vacuum, we mean a space completely free of any matter - an absolute void. Surprisingly, all the bodies around us consist of void. Even we have more vacuum than matter. This is true: if it were possible to bring the electrons close to the nuclei in our atoms, our body's size would be reduced by 100,000 times, but the mass would remain the same.

If no precautions are taken, hitting the water can cause severe injuries. To avoid injuries, athletes spend many years learning to group and penetrate the water relatively freely, which gradually reduces the speed of the person.

In fact, this will lock the wheels and the car will skid. It all comes down to friction. In different situations, the wheels and the car itself behave differently, which must be remembered while driving.

When running in calm weather, wetting will occur not only from above but also from the front. Thus, the faster a body moves, the larger the area that the raindrops hit, consequently increasing the total amount of water that hits the body over a certain period of time.