Tip 1: How to increase kinetic energy
Tip 1: How to increase kinetic energy
Kinetic energy has a body that moves. It is its change that is the result of mechanical work. Increase kinetic Energy You can, by working on the body or changing its parameters.
You will need
- - the concept of mechanical work;
- - the concept of mass and speed;
- - calculator.
Instructions
1
In the general case, increase the kinetic Energy body, having done work on it. To do this, act on the body by force, which will move it a certain distance so that the body increases its speed. The work done on the body will be equal to the increase in its kinetic energy. For example, if it is known that the engine's thrust force is 2000 N, then for 100 m the work will be done equal to the product of the force at a distance A = 2000 • 100 = 200000 J. This will be the value by which the kinetic energy of the car has increased.
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Increase kinetic Energy can be in other ways. Since this value depends on the mass and velocity of the body (it is equal to half the product of the mass of the body m by the square of the velocity of the body v; Ek = m • v? / 2), change these parameters. If you find the possibility to increase the body weight at the same speed as it has, then its kinetic energy will increase by the same amount as the body weight increased. For example, increasing the mass of a moving train by two times, you will get the same increase in its kinetic energy.
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It is more effective to increase the kinetic Energy by increasing the speed of the moving body. This is due to the fact that the kinetic energy is directly proportional to the square of the velocity. Thus, with an increase in the velocity of the body by a factor of n, the kinetic energy will increase in n ?. For example, if the speed of a moving body is increased 3 times, then its kinetic energy will increase 9 times.
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Example. How many times will the kinetic energy of the train increase, if the mass of the train is doubled in the result of loading, and it moves at a speed that is 1.5 times higher than the one it had when it moved empty. Since the kinetic energy is calculated by the formula Ek = m • v? / 2, where m is the mass of the body, and v is its velocity. With increasing mass and velocity, according to the condition, we obtain: Ek = 2 • m • (1.5 • v)? / 2 = 2 • 1.5? • m • v? / 2 = 4.5 • m • v? / 2. The kinetic energy will increase by 4.5 times.
Tip 2: How to find kinetic energy
Kinetic energy is the energy of a mechanicalsystem, which depends on the velocities of each of its points. In other words, the kinetic energy is the difference between the total energy and the rest energy of the system under consideration, that part of the total energy of the system that is due to motion. The kinetic energy is divided into Energy translational and rotational motion. The unit of measurement of the kinetic energy in the SI system is Joule.
Instructions
1
In the case of translational motion, all pointssystems (bodies) have the same speed of movement, which are equal to the speed of motion of the center of mass of the body. In this case, the kinetic energy of the system Тпост is equal to: Тпост =? (mk Vc2) / 2, where mk is the mass of the body, Vc is the velocity of the center of mass. Thus, with the translational motion of the body, the kinetic energy is equal to the product of the mass of the body per square of the velocity of the center of mass divided by two. In this case, the value of the kinetic energy does not depend on the direction of motion.
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When rotating, when the body rotatesaround any axis Oz, the velocity of any of its points determines the equation: Vk =? hk, where hk is the distance of the given point to the axis of rotation,? angular velocity of the body. If we substitute the equation that determines the speed of a point in an expression and put the common factors in parenthesis, we obtain the equation of the kinetic energy of the system in the case of rotational motion: Tpp =? (mk? 2 hk2) / 2 =? (mk hk2)? 2 / 2Expression in parentheses is the moment of inertia of the body, relative to the axis around which the body rotates. Hence we obtain: Tpp = (Iz2) / 2, where Iz is the moment of inertia of the body. Thus, with the rotational motion of the body, its kinetic energy is equal to the product of the moment of inertia of the body relative to the axis of rotation by the square of its angular velocity divided in half. In this case, the direction of rotation of the body does not affect the values of its kinetic energy.
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In the case of an absolutely rigid body, the total kinetic energy is equal to the sum of the kinetic energies of the translational and rotational motions: T = (mk Vc2) / 2 + (Iz2) / 2
Tip 3: How to increase energy
Do you often feel powerless at the end of the day? Lack of energy is one of the most common complaints among people of all ages, but the older you become, the harder it becomes to cope with it. Sometimes it happens because of some disease, sometimes it depends on the way of life. However, many effective ways to increase Energy. They will help with any of the cases.
You will need
- Diet
- Sleep
- Strength of will
- Meditation
Instructions
1
Make sure that your diet is sufficientthe amount of vitamin D. Its deficiency causes a general weakening of the muscular system. Take it in the form of food additives and do not forget about ten minutes of sunbathing (natural sun) per day - these procedures will significantly raise the level of vitamin D.
2
If you follow a diet, the absenceenergy is a natural process. Do not limit yourself to calories too much (1200 is the lower limit where you can go down). And make sure that every day your diet includes proteins and useful slow carbohydrates (for example, whole grain bread).
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If you smoke, drop it. Smokers often lack oxygen, and this leads to swelling and reduced energy.
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Finally, to increase Energy, sleep! Lack of sleep is the most common reason for the lack of energy. If you sleep less than eight hours a night, it's time to rethink your biological schedule.
Tip 4: How to find the average kinetic energy of molecules
Molecule is the object of the microcosm. Therefore, a direct measurement of its kinetic energy is impossible. The average kinetic energy is a statistical concept. This is the average value of the kinetic energies of all the molecules entering the substance.
You will need
- - periodic table of chemical elements;
- - thermometer;
- - calculator.
Instructions
1
Find the average kinetic Energy, using the mean molecular velocitysubstance. Calculate the mass of one molecule of matter. To do this, determine its molar mass in kilograms per mole using a periodic table of chemical elements. To do this, find the relative atomic masses of all the elements that make up the molecule of matter. They are indicated in the corresponding cells of the table. Add them, and get the relative molecular weight of the molecule. Divide this number by 1000 and get the molar mass of the substance in kilograms per mole.
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Divide the molar mass by the Avogadro number (NA = 6.022 ∙ 10 ^ 23 1 / mol) and get the mass of one molecule of substance m0 in kilograms. Calculate the average kinetic Energy molecules, multiplying the mass of one molecule m0 by the square of its velocity v, and divide the result by 2 (Ek = m0 ∙ v² / 2).
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Example. Calculate the average kinetic velocity of nitrogen molecules if their average velocity is 100 m / s. The molar mass of a diatomic nitrogen molecule is 0.028 kg / mol. Find the mass of one molecule 0,028 / (6,022 ∙ 10 ^ 23) ≈4,6 ∙ 10 ^ (-25) kg. Determine the average kinetic Energy of the molecules Ek = 4.6 ∙ 10 ^ (-25) ∙ 100² / 2 = 2.3 ∙ 10 ^ (-21) J.
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Find the average kinetic Energy of gas molecules through the temperature value. Measure this value with a thermometer. If the instrument measures in degrees Celsius, translate the temperature value into Kelvin according to the absolute scale. To do this, add the number 273 to the temperature value in degrees Celsius. For example, if the gas temperature is 23 ° C, then on the absolute scale its temperature will be equal to T = 23 + 273 = 296 K.
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Determine the degree of freedom of the molecule i. This value for a monatomic molecule is 3. For a diatomic particle - 5, triatomic and more - 6. Calculate the average kinetic Energy, multiplying the degree of freedom of the molecule by the absolute gas temperature and the Boltzmann constant (k = 1.38 ∙ 10 ^ (-23)). Divide the result by the number 2 (Ek = i ∙ k ∙ T / 2).
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Example. Find the average kinetic Energy molecules of a diatomic gas at a temperature of 85 ° C. Determine the gas temperature according to the absolute scale T = 85 + 273 = 358K. The degree of freedom of a diatomic molecule is i = 5. Make the calculation of Ek = 5 ∙ 1.38 ∙ 10 ^ (-23) ∙ 358 / 2≈1.24 ∙ 10 ^ (-20) J.
Tip 5: How to increase the high jump for basketball
Kinds of sport where the aforementionedskill, sufficient number. But to pay the main attention is all the same on the game programs - such as basketball or volleyball. That's where it is, where it's really vital to be able to jump high. Especially given the height at which the net stretches and the ring for the ball is attached. That's why experienced coaches follow a few simple tricks that help the athlete develop the necessary muscle groups.
Instructions
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The simplest and most effective way -use weighting. It's worth starting from the belt. But there is one "but" - running around with a similar unit on the body is not entirely convenient. And it's not entirely safe. After all, thanks to the belt, the weight of the athlete increases, which, in turn, increases his kinetic energy during the movement. This, first, reduces the maneuverability and mobility of the player, and secondly, in the event of a collision, the injuries will be more serious.
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It is to ensure that no one is hurt, evenbasketball players dressed in weight belts, it is necessary to force to play volleyball. What is the fundamental superiority of this game in front of basketball? There is no need to run much, and the risk of a collision of players is reduced to a minimum. And given the fact that the net stretches quite high, players will often have to jump a lot to intercept the flying ball.
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It promotes the development of leg muscles, hiparea, back, waist and press. Plus, the endurance of the players develops. When such weighting units are removed, it will become much easier to make high jumps, because the muscles will have time to get used to the weight that the belt added to them.
