Physical problems Hammers and feathers are laid down at the same height on the moon

- The speed of fall is not related to mass, it is related to volume.

You can look at the explanation of Galileo's experiment, where two iron balls hit the ground at the same time to show that it has nothing to do with mass. If there is no resistance, the gravitational acceleration is the same, and the initial velocity is 0, so velocity and mass are not related. Moreover, the formula also shows that in the free fall motion, the force determines the acceleration due to the air resistance.

In fact, speed has nothing to do with time, not with mass, but with volume. The larger the volume, the greater the air resistance and the slower the falling speed.

Aristotle thought so, too.

You can think about it, glue the hammer and the feather together, and then do the experiment, is this combination faster or slower than the hammer falling?

1. Because it sticks together, the total weight is heavier, so it should be faster.

2. Because the feathers are slow, they will drag the fast hammer, so it is slower than the hammer alone.

Then both of the above make sense and contradict each other, so the assumption that the hammer is fast is wrong.

As long as there is no air resistance and only gravity, they all fall to the ground at the same time!

Have you ever learned the law of ox two? f=ma shows that as long as the gravitational acceleration is the same as long as it is on the same planet, then as long as the altitude is the same, the time taken is the same. This is the content of the first semester of high school.

It's like adults do more work than villains, but the amount of food is also bigger than villains! So they eat just as much.

If the landlord has the site conditions, he might as well do the experiment himself, Galileo is the Aristotle who relied on the experiment to overthrow.

The attraction of the Moon to objects is about 1 6 of the Earth's A person can lift 200 kg of objects on the Earth, then the mass of the object he can lift on the Moon is 1200 kg.

The weight of an object that a person can lift on the Earth and on the Moon is the same.

On Earth: g = 200g

On the Moon: g = m (g 6) = mg 6

200g=mg/6

m=200*6=1200kg

To the moon he can lift the mass of the object is 1200kg.

On the Moon, he can lift six times the mass of an object that can be lifted on Earth.

Throw an iron ball of equal mass from the same height as the paper ball, and if it were on Earth, the iron ball would have landed first. It should be that the density of iron is greater than the density of paper, and the volume of the paper ball is larger in the case of the same mass, then the windward area is larger, and the paper ball is subject to greater air resistance according to f=(1 2)C sv 2.

where: c is the air resistance coefficient; for air density; s Frontal area of the object; v is the relative velocity of the object and the air. From the above equation, it can be seen that under normal circumstances, the magnitude of air resistance is proportional to the air resistance coefficient and the windward area, and is proportional to the square of the velocity. ）

If a small piece of iron and a feather are released at the same place and at the same height on the moon, then they will land at the same time, because they are only subject to gravity, not by air resistance, and the acceleration is the same.

On the earth, it is the iron ball that lands first, because the air resistance has a greater effect on the paper ball, so the iron ball falls first.

On the moon, they land at the same time, because there is no air on the moon, so there is no resistance, and their acceleration is the same, so they will land at the same time.

On Earth, considering the presence of air, its resistance has a greater impact on the paper ball, so the iron ball falls first.

On the moon without air, if the two objects have equal mass, then they land at the same time.

If the shape is the same, and the air resistance is f=6rv when it lands at the same time

On Earth, lifting 20 kg means that the maximum pressure he can withstand is f = mg = 200 n, which is a fixed value (determined by this person).

The maximum pressure he is under on the moon is still f=200n, and the amount of bend he lifts is m, and if there is f=mg month=mg 6, then the rock stuff m=120kg

It is known from the inscription: g month = g 6).