The third year of science kinetic energy and potential energy, the internal energy of objects, and

1.Who told you to choose B? It's very simple, according to the following formula:

Power p = ui = 6v * a = w, answer a;

Minutes consume kilowatt hours of electrical energy, that is, one hour consumes kilowatt hours, that is, the power of this appliance is 1200W, and the radio: the power consumption is very small, at most a few W.

Color TV: (19 inches-42 inches)--80w--250w

Refrigerator: 150W up and down.

Air conditioning: The air conditioner of the horse 1200w 1500w bedroom is like this, about 20. The cabinet machine is generally horsepower, and the power is above 3000W and below 5000W.

Thus it is a air conditioner;

3.By the specific heat formula.

c=q (m δt), the amount of energy it takes to raise the temperature of the water is equal to the amount of energy it takes to burn coal to reach the same water temperature.

Thus q (water) = c (water) m (water) δt = q (coal) = calorific value (coal) v (coal), i.e. v (coal) = [ c (water) * m (water) * δt ] calorific value (coal) = [cubic meter.

1 p = ui-= 6v x = so it is impossible to choose b if you choose a.

2 p= w t = = kwh That is to say, the power of the electrical appliance reaches kw, so it can only be an air conditioner.

3 q= cm（t1 - t2 ）= 100㎏ x （80℃-30℃）= x 10^7 j

m coal = x 10 7 j = m3

Kinetic energy is the energy possessed by physical motion, which is determined by its mass and velocity, ek=(mv 2) 2, a small ball hitting you at a speed of 1m s is not the same as hitting you at a speed of 10m s;

Potential energy is the energy stored in a system, and this energy is waiting to be released or transformed, for example, gravitational potential energy is determined by mass and height under the same gravitational acceleration, ep=mgh, for example, the result of an egg falling from 1cm is not the same as falling from 1m, it is the egg that stores more energy at a high place than at a low place, and when it falls freely, the cave is the process of converting this stored ability into kinetic energy; Another example is the elastic potential energy, ep=( kx 2) 2, the energy stored when the spring is compressed or elongated;

These are all related to macroscopic mechanical motion, the velocity, height, compression length of the object, etc., are all mechanical energy; Internal energy is related to thermal motion, which is the ability of the microscopic molecules in the object to move quietly, such as the kinetic energy of the molecule when it does irregular thermal motion, the potential energy of the molecule, etc., which is embodied in the form of temperature, volume, mass, etc., such as a red-hot iron block, which has a high energy, and this energy is completely different from mechanical energy.

The most intuitive conversion of mechanical energy and internal energy is friction, the small iron block moves in a rough plane, and it is getting slower and slower when there is no external force, and the heat generated by friction is the internal energy converted from kinetic energy.

There are many transformations of potential energy and kinetic energy, such as falling from a high place, his gravitational potential energy decreases, but kinetic energy increases; The speed of throwing the ball upwards is getting smaller and smaller, the height is getting higher and higher, the kinetic energy is decreasing, and the potential energy is increasing; The spring from extension to contraction, from contraction to extension is the process of converting internal energy into kinetic energy, and then there is the process of converting kinetic energy into internal energy.

The ability of the whole transformation process is conserved, as long as the energy difference is found, the increase and decrease are the same, and all the problems encountered at present can be solved. For example, falling from a height, mgh1-mgh2 is the amount of potential energy decrease, (m(v2) 2) 2-m(v2) 1) 2 is the amount of kinetic energy increase, they are equal; Or in the rough motion plane, m(v2) 2) 2-m(v2) 1) 2) 2 is the amount of kinetic energy increase or decrease, q is the amount of internal energy increase, and they are both equal.

Kinetic energy and potential energy are collectively referred to as mechanical energy; The conversion of kinetic energy and potential energy often occurs when an object falls or throws upward, and when the fall accelerates and falls, the gravitational potential energy is converted into kinetic energy. On the contrary, the kinetic energy is converted into gravitational potential energy.

Internal energy is the sum of the kinetic energy and molecular potential energy of all the molecules that make up the material to move irregularly, and the mechanical energy conversion often occurs when "friction generates heat", and the mechanical energy is converted into internal energy; A typical example of the conversion of internal energy into mechanical energy is a heat engine.

The work done by the combined external force corresponds to the change in kinetic energy (kinetic energy theorem).

Potential energy includes electric potential energy (corresponding to electrical energy doing work), gravitational potential energy (corresponding to gravitational work), elastic potential energy (corresponding to elastic force doing work).

The mechanical energy trapped brigade is divided into one object and multiple objects. In the case of an object, the mechanical energy includes kinetic energy and gravitational potential segment ruler energy, which corresponds to the work done by forces other than gravity; In the case of multiple objects, the mechanical energy includes kinetic energy, gravitational potential energy, and elastic potential energy, which corresponds to the work of other forces other than gravitational elastic force.

Internal energy is the work done by sliding friction multiplied by the relative displacement.

The transformation between energies is the transformation between forces and work.

According to the law of conservation of energy, they are all interchangeable.

The following objects have only kinetic energy (b), where the ground is the reference plane for zero potential energy;

The only potential energy is (d and e), where the former has the geocentric as the zero potential energy reference surface, and the latter has the sea level as the zero potential energy reference surface;

The ones that have both kinetic and potential energy are (a and c), where the ground is used as the reference plane for zero potential energy.

If the ground is taken as a zero potential energy surface, then the object that is moving in the air has both kinetic and potential energy.

Choose A and C

The kinetic energy of an object is related to the mass of the object, the magnitude of its velocity.

ek＝mv^2 / 2

Note: Kinetic energy is the title and has nothing to do with the direction of velocity.

The kinetic energy of an object is related to the mass of the object, the magnitude of its velocity.

ek＝mv^2 / 2

In classical mechanics, momentum (kg·m s in the International System of Units) is expressed as the product of the mass and velocity of an object, and is a physical quantity related to the mass and velocity of an object, which refers to the tendency of the object to maintain motion in the direction of its motion.

It is related to the mass and velocity of the object.

The energy possessed by an object that is related to motion is called mechanical energy (kinetic energy).

Internal energy refers to the sum of the kinetic energy and the potential energy of the interaction between the molecules of all the molecules in the object, and the unit of internal energy is joules

Therefore, the answer is: all molecules do Lingna irregular movement; Joules

The energy possessed by an object due to is called kinetic energy, and the energy possessed by an object due to is called gravitational potential energy; The energy that an object has due to the occurrence of brightness is called elastic potential energy, and kinetic energy and potential energy are collectively referred to

Answer (Find homework answers --- on the Rubik's Cube).

Reproducing Physics Knowledge:

The energy that an object has due to motion and the object is in motion is called kinetic energy;

The energy that an object has due to being lifted is called gravitational potential energy;

The energy possessed by an object due to elastic deformation is called elastic potential energy;

Mechanical energy is the sum of kinetic energy and potential energy

So the answer is: exercise; to be lifted high; elastic deformation; Mechanical energy

Kinetic energy refers to the energy that an object has due to its motion, and its magnitude is related to the mass of the object and the speed of the object.

So the answer is: exercise; Quality; Speed

The energy possessed by the object due to is called kinetic energy, and the energy possessed by the object due to is called the gravitational potential circular energy; The energy that an object has due to its occurrence is called elastic potential energy, and kinetic energy and potential energy are both called in bright terms

Answer. Reproducing Physics Knowledge:

The energy that an object has due to motion and the object due to motion is called kinetic energy;

The energy of the object due to the lifting of the clear bond is called gravitational potential energy;

The energy possessed by an object due to elastic deformation is called elastic potential energy;

Mechanical energy is the sum of kinetic energy and potential energy

So the answer is: exercise; to be lifted high; elastic deformation; Mechanical energy

1.Kinetic energy, gravitational potential energy 2Gravitational potential energy and elastic potential energy (if the slight deformation of the rope is taken into account).

3.Gravitational potential is like kinetic energy 4Elastic potential energy 5Elastic potential energy 6Kinetic energy and gravitational potential energy ......

There is gravitational potential energy on the earth, as long as Yunzhen Sun Dong has kinetic energy, there is elastic potential energy if there is elastic deformation) slag and.