Body weight on different planets. Gravity on the moon and planets. Do you know that even on Earth your weight is not the same everywhere?
We associate an ordinary classical museum with half-empty echoing halls, dusty exhibits in showcases and the lulling voice of a guide.
However, a new type of museum has been successfully operating in the West for several decades - interactive. The main idea of the interactive museum is not a guide's monologue and a passive examination of the exposition, but the involvement of visitors in interaction with the exhibits. An interactive museum is a great opportunity to spend a few hours of free time pleasantly and profitably. It will be interesting for an individual visitor, a family, and a group of students. We will be glad to see people of all ages in our museum: younger students and their parents, as well as grandparents.
In terms of equipment, Lunarium is not inferior to European scientific centers and museums. It is located on two floors and consists of sections "Astronomy and Physics" and "Comprehension of Space". The exposition features more than eighty exhibits that visually demonstrate various physical laws and natural phenomena in a playful way. Here, the manifestations of the laws of nature are sometimes graphic, sometimes funny, sometimes look like a miracle. The exposition of the section "Astronomy and Physics" introduces us to the wonderful world of science, where each exhibit is a real scientific laboratory, where every visitor can feel like an experimental scientist. Here you can create artificial clouds and tornadoes, generate electrical energy, compose electronic music, ride a space bike and find out your weight on other planets. And such exhibits as "Black Hole", "Hyperboloid Magic Wand", "Ferrofluid Hedgehog", "Plasma Ball" and "Optical Illusions" will certainly arouse extraordinary interest among visitors, a lot of questions and heated discussions. The grandiose Foucault pendulum will convince all visitors that the Earth rotates around its axis, and Tellurium will illustrate the change of day and night and the seasons.
The exposition "Comprehension of space" is designed in the form of a space station with thematic compartments. Moving from one compartment to another allows you to make an Interplanetary Voyage, visit the Lunar Laboratory, get acquainted with the history of the Big Bang and travel to infinity! Along the way, you can make observations through telescopes of various optical systems, save the planet from asteroids, send a message to aliens, launch air and hydrogen rockets, learn the properties of weightlessness and vacuum.
Each exhibit is equipped with a colorful sign that will help you get all the information you need to explore the exhibits on your own. If necessary, consultants in the hall will come to the rescue - senior students and graduates of the Faculty of Physics of Moscow State University. They will explain the purpose and principles of operation of the respective exhibits and answer all questions.
For school groups, thematic and educational excursions are provided, accompanied by qualified guides. The interactive museum is liberation. Here, every adult can once again feel like a child-discoverer, and together with children get vivid and unforgettable impressions. And children can try themselves in the role of scientists-researchers. Most importantly, here it becomes clear that knowledge is born from experiments and observations.
The interactive museum is a fabulous kaleidoscope of interesting, unforgettable experiments and discoveries, a real feast for the living imagination. We are waiting for you at our place and hope that you will be our frequent and welcome guests. See you at Lunarium!
Objects or people, such as the hopping astronaut shown in the figure, weigh less on the Moon than on Earth, due to the weaker gravitational field of the Moon. Gravity is the fundamental gravitational force that propagates through outer space and acts on all physical bodies.
The gravitational attraction between any two bodies, for example, between a planet and a person, can be quantified if the mass of each body and the distance between them are known. Mass, which remains constant, is a quantitative measure of the matter contained in the body. As for weight, it is a measure of the force of gravity acting on a body. The stronger the gravitational field, the greater will be the weight of the body and the higher will be its acceleration; the weaker the gravitational field, the less will be the weight of the body and the less acceleration it will experience. The force characteristics of gravitational fields depend on the size of the bodies they surround, so the weight of any body is not a fixed value.
On the image Moon(left) and Earth(on right):
- On the Moon, an astronaut's weight is reduced by six times compared to his weight on Earth, since the force of gravity on the Moon is only one-sixth of that of Earth.
- Upon returning from the moon (fig. on the right), the astronaut shown in the figure below the text weighs six times more on Earth than he weighed on the Moon. Having more mass than the Moon, the Earth develops a higher gravitational attraction force.
Like stones in a well
In the gravitational fields shown schematically in the figure below the text, the Moon (left side of the picture) creates a smaller force of attraction than the more massive Earth (right side of the picture). Overcoming gravity is like climbing out of a well. The greater the force of gravity, the deeper the well and the steeper its walls.
The essence of the mutual gravity of bodies
The Moon and the Earth (respectively, the left and right drawings above the text) attract bodies that are near their surface; bodies in turn also create an attractive force proportional to their mass. The greater distance between the Moon and the person in the left figure and the smaller mass of the Moon contribute to a weaker gravitational connection, while for the couple in the right figure, the greater mass of the Earth provides a stronger attraction.
The average mass of the moon is about 7.3477 x 1022 kg.
The Moon is the only satellite of the Earth and the closest celestial body to it. The source of the Moon's glow is the Sun, so we always observe only the lunar part facing the great luminary. The second half of the Moon at this time is immersed in cosmic darkness, waiting for its turn to come out "to the light." The distance between the Moon and the Earth is approximately 384,467 km. So, today we will find out how much the Moon weighs compared to other "inhabitants" of the solar system, and also learn interesting facts about this mysterious earthly satellite.
Why is the moon called that?
The ancient Romans called the moon the goddess of the night light, whose name the night star itself was eventually named. According to other sources, the word "moon" has Indo-European roots and means "bright" - and for good reason, because in terms of brightness the earth's satellite is in second place after the Sun. In ancient Greek, a star shining with a cold yellowish light in the night sky was called the name of the goddess Selene.
What is the weight of the moon?
The moon weighs about 7.3477 x 1022 kg.
Indeed, in physical terms, there is no such thing as “the weight of the planet”. After all, weight is the force exerted by a body on a horizontal surface. Alternatively, if the body is suspended on a vertical thread, then its weight is the tensile force of the body of this thread. It is clear that the Moon is not located on the surface and is not in a "suspended" state. So, from a physical point of view, the moon has no weight. Therefore, it would be more appropriate to talk about the mass of this celestial body.
The weight of the moon and its movement - what is the relationship?
Since ancient times, people have tried to unravel the "mystery" of the movement of the Earth's satellite. The theory of the motion of the Moon, first created by the American astronomer E. Brown in 1895, has become the basis of modern calculations. However, to determine the exact motion of the moon, it was necessary to know its mass, as well as various coefficients of trigonometric functions.
However, thanks to the achievements of modern science, it became possible to carry out more accurate calculations. Using the laser location method, you can determine the size of a celestial body with an error of just a couple of centimeters. So, scientists have revealed and proved that the mass of the Moon is 81 times less than the mass of our planet, and the radius of the Earth is 37 times greater than the similar lunar parameter.
Of course, such discoveries became possible only with the advent of the era of space satellites. But scientists of the era of the great "discoverer" of the law of universal gravitation Newton determined the mass of the moon, exploring the tides caused by periodic changes in the position of a celestial body relative to the earth.
Moon - characteristics and numbers
- surface - 38 million km 2, which is approximately 7.4% of the Earth's surface
- volume - 22 billion m 3 (2% of the value of a similar terrestrial indicator)
- average density - 3.34 g / cm 3 (at the Earth - 5.52 g / cm 3)
- gravity - equal to 1/6 of the earth
The Moon is a rather “heavy” celestial satellite, not typical for terrestrial planets. If we compare the mass of all planetary satellites, then the Moon will be in fifth place. Even Pluto, considered a full-fledged planet until 2006, is more than five times smaller in mass than the Moon. As you know, Pluto consists of rocks and ice, so its density is low - about 1.7 g / cm 3. But Ganymede, Titan, Callisto and Io, which are satellites of the giant planets of the solar system, are larger than the moon in mass.
It is known that the force of gravity or gravitation of any body in the Universe consists in the presence of an attractive force between different bodies. In turn, the magnitude of the force of attraction depends on the mass of the bodies and the distance between them. So, the Earth pulls a person to its surface - and not vice versa, since the planet is much larger in size. In this case, the force of gravity is equal to the weight of a person. Let's try to double the distance between the center of the Earth and a person (for example, let's climb a mountain 6500 km above the earth's surface). Now a person weighs four times less!
But the Moon is significantly inferior in mass to the Earth, therefore, the lunar gravitational force is also less than the force of the earth's attraction. So the astronauts who landed on the lunar surface for the first time could make unimaginable jumps - even with a heavy space suit and other "space" equipment. After all, on the moon, a person’s weight decreases as much as six times! The most suitable place for setting "interplanetary" Olympic records in high jumps.
So, now we know how much the Moon weighs, its main characteristics, as well as other interesting facts about the mass of this mysterious earthly satellite.
Imagine that we are going on a journey through the solar system. What is the force of gravity on other planets? On which ones will we be easier than on Earth, and on which ones it will be harder?
While we have not yet left the Earth, let's do the following experiment: let's mentally descend to one of the earth's poles, and then imagine that we have been transported to the equator. I wonder if our weight has changed?
It is known that the weight of any body is determined by the force of attraction (gravity). It is directly proportional to the mass of the planet and inversely proportional to the square of its radius (we first learned about this from a school physics textbook). Therefore, if our Earth were strictly spherical, then the weight of each object when moving over its surface would remain unchanged.
But the Earth is not a sphere. It is flattened at the poles and elongated along the equator. The equatorial radius of the Earth is 21 km longer than the polar one. It turns out that the force of gravity acts on the equator as if from afar. That is why the weight of the same body in different parts of the Earth is not the same. The heaviest objects should be at the earth's poles and the easiest - at the equator. Here they become 1/190 lighter than their weight at the poles. Of course, this change in weight can only be detected using a spring balance. A slight decrease in the weight of objects at the equator also occurs due to the centrifugal force arising from the rotation of the Earth. Thus, the weight of an adult person arriving from the high polar latitudes to the equator will decrease by a total of approximately 0.5 kg.
Now it is appropriate to ask: how will the weight of a person traveling through the planets of the solar system change?
Our first space station is Mars. How much would a person weigh on Mars? It is not difficult to make such a calculation. To do this, you need to know the mass and radius of Mars.
As is known, the mass of the "red planet" is 9.31 times less than the mass of the Earth, and the radius is 1.88 times smaller than the radius of the globe. Consequently, due to the action of the first factor, the force of gravity on the surface of Mars should be 9.31 times less, and due to the second - 3.53 times greater than ours (1.88 * 1.88 = 3.53 ). Ultimately, it is there a little more than 1/3 of the earth's gravity (3.53: 9.31 = 0.38). In the same way, one can determine the stress of gravity on any celestial body.
Now let's agree that on Earth an astronaut-traveler weighs exactly 70 kg. Then for other planets we get the following weight values (the planets are arranged in order of increasing weight):
Pluto 4.5 Mercury 26.5 Mars 26.5 Saturn 62.7 Uranus 63.4 Venus 63.4 Earth 70.0 Neptune 79.6 Jupiter 161.2
As you can see, the Earth occupies an intermediate position between the giant planets in terms of gravity. On two of them - Saturn and Uranus - the force of gravity is somewhat less than on Earth, and on the other two - Jupiter and Neptune - more. True, for Jupiter and Saturn, the weight is given taking into account the action of centrifugal force (they rotate rapidly). The latter reduces body weight at the equator by a few percent.
It should be noted that for the giant planets, the weight values are given at the level of the upper cloud layer, and not at the level of the solid surface, as for terrestrial planets (Mercury, Venus, Earth, Mars) and Pluto.
On the surface of Venus, a person will be almost 10% lighter than on Earth. On the other hand, on Mercury and Mars, the weight reduction will occur by a factor of 2.6. As for Pluto, a person will be 2.5 times lighter on it than on the Moon, or 15.5 times lighter than on Earth.
But on the Sun, gravity (attraction) is 28 times stronger than on Earth. A human body would weigh 2 tons there and would be instantly crushed by its own weight. However, before reaching the Sun, everything would turn into hot gas. Another thing is tiny celestial bodies, such as the satellites of Mars and asteroids. On many of them, in terms of ease, you can become like ... a sparrow!
It is quite clear that a person can travel to other planets only in a special sealed spacesuit equipped with life support system devices. The weight of orbital spacesuits is about 120 kg (orlan MK, has been in operation since 2009), spacesuits are being developed for other celestial bodies, the so-called space ones, whose weight is about 200 kg. Therefore, the values given by us for the weight of a space traveler on other planets must be at least tripled. Only then will we obtain weight values close to the real ones.
Korottsev O.N.
(based on http://www.prosto-o-slognom.ru)
People have dreamed of traveling to the stars since ancient times, starting from the time when the first astronomers examined other planets of our system and their satellites in primitive telescopes. Many centuries have passed since then, but alas, interplanetary and even more so flights to other stars are impossible even now. And the only extraterrestrial object that researchers have visited is the Moon.
We know that Gravity is the force with which the Earth attracts various objects.
Gravity is always directed towards the center of the planet. The force of gravity tells the body an acceleration, which is called the acceleration of free fall and is numerically equal to 9.8 m / s 2. This means that any body, regardless of its mass, in free fall (without air resistance) changes its speed for every second of falling by 9.8 m / s.
Using the formula to find the free fall acceleration
The mass of the planets M and their radius R are known through astronomical observations and complex calculations.
and G is the gravitational constant (6.6742 10 -11 m 3 s -2 kg -1).
If we apply this formula to calculate the gravitational acceleration on the Earth's surface (mass M = 5.9736 1024 kg, radius R = 6.371 106 m), we get g \u003d 6.6742 * 10 * 5.9736 / 6.371 * 6.371 \u003d 9.822 m / s 2
The standard (“normal”) value adopted when constructing systems of units is g = 9.80665 m / s 2, and in technical calculations they usually take g = 9.81 m / s 2.
The standard value of g has been defined as "average" in some sense the acceleration of free fall on Earth, approximately equal to the acceleration of free fall at a latitude of 45.5° at sea level.
Due to attraction to the Earth, water flows in rivers. A person, jumping up, falls to the Earth, because the Earth attracts him. The Earth attracts all bodies to itself: the Moon, the water of the seas and oceans, houses, satellites, etc. Due to gravity, the appearance of our planet is constantly changing. Avalanches come down from the mountains, glaciers move, rockfalls fall, rains fall, rivers flow from the hills to the plains.
All living beings on earth feel its attraction. Plants also "feel" the action and direction of gravity, which is why the main root always grows down to the center of the earth, and the stem up.
The Earth and all other planets moving around the Sun are attracted to it and to each other. Not only the Earth attracts bodies to itself, but these bodies also attract the Earth to themselves. Attract each other and all the bodies on Earth. For example, the attraction from the Moon causes the ebb and flow of water on Earth, huge masses of which rise in the oceans and seas twice a day to a height of several meters. Attract each other and all the bodies on Earth. Therefore, THE MUTUAL ATTRACTION OF ALL BODIES IN THE UNIVERSE IS CALLED UNIVERSAL GRAVITATION.
To determine the force of gravity acting on a body of any mass, it is necessary to multiply the acceleration of free fall by the mass of this body.
F=g*m,
where m is the mass of the body, g is the free fall acceleration.
From the formula it can be seen that the value of gravity increases with increasing body weight. It can also be seen that the force of gravity also depends on the magnitude of the free fall acceleration. So, we conclude: for a body of constant mass, the value of gravity changes with a change in the acceleration of free fall.
Using the formula for finding the free fall acceleration g=GM/R 2
We can calculate g values on the surface of any planet. The mass of the planets M and their radius R are known through astronomical observations and complex calculations. where G is the gravitational constant (6.6742 10 -11 m 3 s -2 kg -1).
The planets have long been divided by scientists into two groups. The first is the terrestrial planets: Mercury, Venus, Earth, Mars, and more recently Pluto. They are characterized by relatively small size, a small number of satellites and a solid state. The rest - Jupiter, Saturn, Uranus, Neptune - are giant planets, consisting of gaseous hydrogen and helium. All of them move around the Sun in elliptical orbits, deviating from a given trajectory if a neighboring planet passes nearby.
Our "first space station" is Mars. How much would a person weigh on Mars? It is not difficult to make such a calculation. To do this, you need to know the mass and radius of Mars.
As is known, the mass of the "red planet" is 9.31 times less than the mass of the Earth, and the radius is 1.88 times smaller than the radius of the globe. Consequently, due to the action of the first factor, the force of gravity on the surface of Mars should be 9.31 times less, and due to the second - 3.53 times greater than ours (1.88 * 1.88 = 3.53 ). Ultimately, it is there a little more than 1/3 of the earth's gravity (3.53: 9.31 = 0.38). It is 0.38 g of the earth, which is about half as much. This means that on the red planet you can jump and jump much higher than on Earth, and all weights will also weigh much less. In the same way, one can determine the stress of gravity on any celestial body.
Now let's define the stress of gravity on the Moon. The mass of the Moon, as we know, is 81 times less than the mass of the Earth. If the Earth had such a small mass, then the gravity force on its surface would be 81 times weaker than it is now. But according to Newton's law, the ball attracts as if all its mass is concentrated in the center. The center of the Earth is at a distance of an earth radius from its surface, the center of the moon is at a distance of a lunar radius. But the lunar radius is 27/100 of the earth, and from a decrease in distance by 100/27 times, the force of attraction increases by (100/27) 2 times. So, in the end, the gravitational stress on the surface of the moon is
100 2 / 27 2 * 81 = 1/6 earth
It is curious that if water existed on the Moon, a swimmer would feel in the lunar reservoir just as on Earth. Its weight would decrease by a factor of six, but the weight of the water it displaces would also decrease by the same amount; the ratio between them would be the same as on Earth, and the swimmer would be immersed in the water of the Moon exactly as much as he is immersed in ours.
free fall acceleration on the surface of some celestial bodies, m/s 2
Sun 273.1
Mercury 3.68-3.74
Venus 8.88
Earth 9.81
Moon 1.62
Ceres 0.27
Mars 3.86
Jupiter 23.95
Saturn 10.44
Uranus 8.86
Neptune 11.09
Pluto 0.61
As can be seen from the table, an almost identical value of the acceleration of free fall is present on Venus and is 0.906 of the earth's.
Now let's agree that on Earth an astronaut-traveler weighs exactly 70 kg. Then for other planets we get the following weight values (the planets are arranged in order of increasing weight):
But on the Sun, gravity (attraction) is 28 times stronger than on Earth. A human body would weigh 20,000 N there and would be instantly crushed by its own weight.
If we have a space trip to the planets of the solar system, then we need to be prepared for the fact that our weight will change. The force of attraction also has various effects on living beings. Simply put, when other habitable worlds are discovered, we will see that their inhabitants differ greatly from each other depending on the mass of their planets. For example, if the Moon were inhabited, then it would be inhabited by very tall and fragile creatures, and vice versa, on a planet with the mass of Jupiter, the inhabitants would be very short, strong and massive. Otherwise, on weak limbs in such conditions, you simply cannot survive with all your desire. The force of gravity will play an important role in the future colonization of the same Mars.