Zhang Han ran 2 5 kilometers in 15 minutes with Sports World Campus , what is his pace?

You can do the equation like this. kilometers per hour. So his speed is 10 kilometers an hour. That's it.

It's the distance, 15 minutes is the time. According to the relationship between the journey time, the number obtained is its speed.

After taking the kilometer test and taking 15 minutes, then its pace is.

Speed can be equal to the distance traveled divided by time.

So its velocity is 25 divided by 15 points.

Hello, it means that his speed is still okay, and his physical strength and endurance are not bad.

Behind the Mpemba phenomenon, a cup of cold water and a cup of hot water are placed in the freezer compartment of the refrigerator at the same time, which glass of water freezes first? "Of course the cold water froze first! "I believe that many people will not hesitate to do this.

Unfortunately, this answer is wrong. The mistake was discovered by Mpemba, a junior high school student at Magamba Middle School in Tanzania, Africa. One day in 1963, Mpemba found that the hot milk he kept in the freezer of his refrigerator froze before the cold milk of his classmates.

This puzzled him, so he immediately ran to the teacher and asked for advice. The teacher said easily, "You must be mistaken, Mpamba."

Unconvinced, Mpemba tried again, but the hot milk froze before the cold milk. One day, Dr. Osborn, Head of the Department of Physics at the University of Dar es Salaam, visited Mpemba's school. Mpemba mustered up the courage to ask the doctor his question.

Dr. Osborn said, "I can't ask you questions right away, but I promise to do this experiment myself as soon as I get back to Dar es Salaam." As a result, the doctor's experiment was exactly what Mpemba said.

As a result, this phenomenon is known as the "Mpemba phenomenon". For more than 40 years, the "Mpemba phenomenon" has been recognized as truth to this day. It doesn't end there.

In 2004, Yu Shunxi, a girl from Xiangming Middle School in Shanghai, questioned this phenomenon. Under the guidance of Huang Zengxin, a famous science and technology teacher, Yu Shunxi and two other female students began to study the Mpemba phenomenon. They use sugar, water, milk, starch, ice cream and other ingredients to collect.

Zhang Han ran a kilometer with the Sports World Campus in 15 minutes, and his pace was about one minute per kilometer.

2. Set the half-distance to 1500 meters, so that the time of the whole journey can be calculated as 1500 150 + 1500 100 25 (minutes), and then 1500 2 25 120 (meters), which is the average speed of the entire long-distance running process.

150 plus 100 and divide by 2 and you're good to go.

1) When the student ran 100 acres of meters, he was auspicious and reeded t=so the student's speed: v=st100m

With 2) 15km h=, he runs 100 meters faster than a cyclist at 15km h, so the answer is:;

(1) The time of the student running 100 meters t = so the speed of the student: v = st = 100m

(2) 15km h=, he runs 100 meters faster than a cyclist at 15km h, so the answer is:

The average speed of the whole journey is: 100 10=10m s

1m/s=

The trajectory is straight during the 100-meter race, so the displacement of the athlete is s=100m, so the average velocity is:

v=s t100m

10s=10m s=36km h, so ACD is wrong, B is correct, so choose B