How does the pressure on the ice surface change, and when the ice surface increases the pressure, it

1) Gravity g=mg=40 10=400n (2)Average velocity v=s t=80 10=8m s (3)The pressure on the ice surface when sliding on one foot is p=g s=400 pa When Xiaohua stands on both feet, her pressure on the ice surface becomes smaller, because p=g s, g does not change, s becomes larger, so p becomes smaller.

1. As shown in Figure 11, Xiaohua skates quickly on the skating rink, sliding 80m in 10s, the total mass of her and the skate blades is 40kg, and the contact area between each skate blade and the ice surface is known to be 15cm 2. Q: (1) How much gravity does Xiaohua experience?

2) What is the average speed of Xiaohua's glide? (3) What is the pressure of Xiaohua on the ice surface when he slides on one foot? When Xiaohua stood on her feet, she briefly explained the reason.

1. Solution: (1) The gravitational force that Xiaohua is subjected to g = mg = 40 10 ......1 point) = 400(n)....1 point) (2) The average speed of Xiaohua's skating is v=s t=80 10.........1 point) = 8(m s) ....1 point) (3) The pressure of Xiaohua on the ice surface when sliding on one foot f = g = 400n ......1 point) The pressure on the ice when she skates on one foot is p=g s=400 (pa)......1 point) When Xiaohua stands on both feet, her pressure on the ice decreases. ......1 point) Because when standing on both feet, the contact area between the feet and the ice surface increases due to the constant pressure.

1 point).

Solution: (1) The total weight of Xiao Hua and the ice blade g = mg = 40kg 10n kg = 400n (2) The average speed of Xiao Hua skating v = s t = 80m 10s = 8m s (3) The pressure of Xiao Hua's skate blades on the ice surface when she skates on one foot f = g = 400n The pressure of the skate blades on the ice surface when she skates on one foot p = f s = 400n to the 5th power of pa When Xiao Hua stands on both feet, she decreases the pressure on the ice surface through the skate blades. When standing on both feet, the pressure remains the same, and the contact area between the foot and the ice surface through the blade increases, so the pressure decreases.

One person estimates 500n skate blade contact area estimated 15cm2 pressure p=f s=500n

When she stands on her feet, her pressure on the ice surface becomes smaller, (according to p=f s the pressure does not change, the force area becomes larger, so p becomes smaller).

There is a wonderful relationship between the melting point of d ice and the pressure: below 2200 atmospheres, the melting point of ice decreases with the increase of pressure, about 1 degree Celsius for every 130 atmospheres of increase; After exceeding 2200 atmospheres, the melting point of ice increases with increasing pressure: the melting point of ice is -17 at 3530 atmospheres, 0 at 6380 atmospheres, 60 finches at 16500 atmospheres, and water does not freeze until 76 at 20670 atmospheres, which is called veritable "hot ice".

Solution: (1) The total weight of Xiao Hua and the ice blade g = mg = 40kg 10n kg = 400n (2) The average speed of Xiao Hua's skating pants v = s t = 80m 10s = 8m s (3) The pressure of Xiao Hua's skate blades on the ice surface when she skates on one foot f = g = 400n The pressure of the skate blades on the ice surface when she skates on one foot p=f s = 400n to the 5th power PA When Xiao Hua stands on both feet, the pressure of her skate blades on the ice surface of the cavity pure ice surface decreases. Because when standing with both feet, the pressure remains the same, and the contact area between the foot and the ice surface through the Wuzhou ice blade increases, so the pressure decreases.

1) Gravity g=mg=40 10=400n(2)Average velocity v=s t=80 10=8m s(3)The pressure on the ice surface when sliding on one foot is p=g s=400 pA When Xiaohua stands with both feet smiling, her pressure on the ice surface becomes smaller, because the key acacia is p=g s, g does not change, s becomes larger, so p becomes smaller.

The hardness of the ice surface affects the speed of the athlete, and the harder the ice, the faster the athlete.

As we all know, the development of the Winter Olympics has very high requirements for the venue, among which the speed skating project will also be affected by the venue, especially in the early stage, until the birth of the modern indoor speed skating hall, so that the wind direction, wind force, temperature, ice surface and other objective factors on the athlete impact gradually decreased, but even so, the host country due to the altitude, climate, geographical location, venue construction specifications of the difference, resulting in athletes in different competitions, the gap is still large.

At present, there are several factors that affect the performance of ice sports, such as ice surface hardness, venue temperature, altitude, etc

Ice surface hardness: The hardness of the ice surface has a great impact on the performance of athletes, and even ice wrestling accidents can occur, and the quality of the ice rink used in speed skating events at the Turin Winter Olympics and the Vancouver Winter Olympics is relatively average, which leads to criticism from participating athletes.

Venue temperature: The temperature of the field will also affect the performance of athletes, and the low temperature will make the participants consume more physical energy and affect the final result. In severe cases, it may even cause injury to the participants.

Altitude: The altitude of the arena also affects performance and is the most important factor, as the higher the altitude, the thinner the air and the less resistance. For example, the altitude of the Harbin station is 128 meters, which is a plain race, and the altitude of the competition venue in the United States is 1425 meters, which is the highest indoor venue in the world.

In short, there are many factors that affect the speed of athletes, and ice hardness is one of them.

The ice pressure increases and the melting point decreases.

The relationship between melting point and pressure varies from substance to substance. Looking at the phase diagram is the easiest to confuse to explain the problem of changing the chain stove, the longitudinal core axis is the pressure, draw an isobaric line horizontally, and the intersection of the isobaric line and the solid-liquid line is the melting point under the pressure.

For elemental matter, there are those where the melting point increases with pressure: for example, CO2, and iodine.

There are also lowered: water is a typical example.

The condition of the water surface after the ice melts:

1.The ice floats on the surface of the water and does not change when it melts.

2.Due to the lack of water, the ice sinks to the bottom, and the water level rises after melting.

You're probably talking about the second scenario.

Known: M people.

45kg, m sled.

10kg，g=10n/kg，p=

Pa Seek: In order to safely pass through the ice surface, the minimum contact area between the Shenzen sled and the ice Solution: The pressure of the sled on the ice surface:

f=g=(m people.

m sledding. g = (45kg + 10kg) 10n kg = 550n, according to the muffled dust p = f

In order to safely cross the ice surface, the contact area between the sled and the cover ice is at least: s=fp550n

A: The contact area between the sled and the ice is at least.