Why doesn t the stone sink when the water is floating?

The surface of the water is also the surface of the substance, and the stone hitting the water surface also has a reaction force, which is equivalent to the stone on the water surface**;

But after all, water is a fluid, and while providing ** force, it also deforms, consuming the kinetic energy of the stone, so the stone will eventually fall into the water;

The key to whether the stone can float is the size of the area that comes into contact with the water. Because this area directly determines the amount of water applied by the stone, and also determines whether the vertical momentum of the stone will gain vertical upward velocity after sharing with the water. If you want to study this carefully, you have to combine the conservation of momentum and the conservation of energy.

The smaller the angle of incidence, the greater the fractional velocity in the vertical direction of the velocity, resulting in the stone being embedded too deep in the water surface when interacting with the water, and the resistance in the horizontal direction increases, reducing the possibility of the stone floating.

To sum up: general objects have a tendency to float up, because it is a plane ** effect, but the degree of energy loss is different, resulting in different results. In general, the larger the angle of incidence, the greater the contact surface with the water surface, and the greater the possibility of floating.

However, the amount of floating has a lot to do with the quality and shape of the stone. And in this case, the effect of tension is negligible.

Because of inertia. He's constantly turning.

collided with the surface of the water, and because of the relative effect.

The stone hits the water, and the water exerts force on the stone at the same time.

And the stone flew up again.

Categories: Education, Science, >> Learning Aid.

Problem description: Why does the stone not sink into the water when it is floating in the water?

Analysis: The higher the flow rate, the less hydraulic pressure there is.

Therefore, when playing water drifting, you should use a relatively flat object (large force area) to throw it out as fast as possible parallel to the water surface (to obtain a comparative flow rate), when the object of water drifting passes over the water surface, it can drive the water above and below to flow rapidly in a very short time, so that the pressure is reduced, and the water below is stationary, and the pressure generated is strong, the object can be pressed out of the water, and then there is a second time or so on more objects into the water.

In addition, the thrown object can be rotated to achieve better results, because the flow rate of the water in contact with it is faster, and the pressure is reduced.

The principle of water drifting is that the higher the flow velocity, the smaller the hydraulic pressure.

Generally speaking, stones or tiles will sink if they fall into the water, and those who can't float will fall directly into the water if they throw the stones. In fact, the principle of water drifting is fluid pressure - the higher the flow velocity, the lower the pressure.

When your stone touches the surface of the water, push the water down a little bit, which will cause the surface of the water to flow rapidly. However, the water remains still if it is not bounced off. In this way, the pressure on the surface of the still part of the water is stronger than the pressure of the fast-flowing water, which creates an upward elastic force that bounces the stone away.

World record

According to the Guinness Book of World Records, the world record for water rafting is 88 bounces, which was set by American Kurt Steiner in 2013.

Professor Tad Trascott and his colleagues at Brigham Young University in Utah, USA, have shown that the technique depends on the angle chosen by the thrower to throw the object, with the ideal throwing angle for saucer stones being close to 20°. However, the heavier the object being thrown, the less chaotic the cast should be.

Because it's fast.

Rafting by the river or sea is a common game or sport. Instead of throwing a stone and falling directly into the water, we often choose the shape of the stone. The angle and intensity of the throwing method will have a big impact on the distance the stone floats.

The stone flies to the surface of the water at a certain speed. Under the action of viscosity, a part of the liquid that is in direct contact with the stone acquires the same velocity as the stone in a short time. The upper layer moves faster as compared to the liquid that is not in direct contact with the lower layer.

According to Bernoulli's principle, the pressure at high flow velocity is less, and the pressure in the lower layer is higher than in the upper layer, resulting in an upward pressure. Under sufficiently large pressure conditions, the downward velocity of the stone can be reduced to zero and accelerated in reverse, resulting in an upward velocity. The above is a qualitative explanation for the generation of water drift.

Obviously, the stone can only float further by minimizing the gravity of the stone itself and increasing its buoyancy, that is, the pressure created by the pressure difference. Therefore, the smallest stone block should be chosen as flat as possible to increase its buoyancy and reduce its dead weight, while the throwing angle should be smaller to obtain greater lateral velocity and reduce vertical velocity. Of course, in order to get more accurate results, more accurate analysis and experimental results are needed.

From a macro perspective, kicking water isn't much different from throwing a basketball on the ground. The result is that the thrown object will jump for a while before stopping. Physically consider the case of throwing a basketball, where the thrown basketball does a horizontal throwing motion, collides with the ground, reverses the downward velocity of the basketball, and continues to do an inclined upward throwing motion, which is similar to the skimming motion.

In other words, in the short time that the stone touches the surface of the water, it happens that the stone velocity produces an upward velocity.

So that's the charm of playing in the water, it's that you can play like this.

I think that if you throw a stone diagonally, the stone will be affected by the force of water.

I think it may be caused by a certain amount of focus.

I think this is because the water surface is relatively open and has an upward buoyancy.

It's a matter of physics. Study physics.

The stone floats away on the water, and there are three main forces acting on the stone: the thrust and resistance of the water on it, and the gravity of the stone itself. The direction of the resultant force formed by the three forces is the direction in which it is moving.

The faster the stone is on the water, it means that the thrust of the water on it is much greater than the resistance of the water to it, so it does not sink, or sinks slowly and for a long time.

The surface of the water has a surface tension force. For an object to shoot into a body of water, it needs a certain force; Edition.

Water has resistance. Objects need a right.

A fixed force can enter the water;

Water also creates a reaction force. When you hit the surface of the water with your hand, the surface of the water also hits your hand, and the force of action and reaction is equal;

When playing in the water, the object does not hit the water surface head-on (vertically), but shoots diagonally towards the water surface, with an angle of incidence. The force of the water drift decomposes into an oblique force and the component of the forward force entering the water is reduced, so that the object is reflected, and the direction of the reflection force is the reflection angle, so that the object pops out to the reflection angle without entering the water. Only when the angle of incidence is small enough can the drift be successful;

The contact between the sheet object and the water with a wide surface can increase the contact surface and increase the resistance, so that the object **. Therefore, it is easy to succeed only if the flaky object is drifting.

That's where the reaction force comes in.

The higher the flow rate, the lower the hydraulic pressure.

Therefore, when playing water drifting, you should use a relatively flat object (large force area) to try to flatten the bucket and move on the water surface as fast as possible to throw it out (to obtain a comparative flow shed seepage velocity), when the object of water drifting passes over the water surface, it can drive the water up and down it to flow quickly in a very short time, so that the pressure is reduced, and the water below is stationary, the pressure generated is strong, the object can be pressed out of the water, and then there is a second time or so on more times the object enters the water.

In addition, the thrown object is rotated to achieve better results, because the water in contact with it flows faster, and the pressure is reduced.

It is certainly not because of buoyancy, but according to Archimedes' law, the buoyancy is greatest when the stone is completely in the water!