Which will fall first, the sphere or the block? Why.

According to the conservation of energy, if the mass is the same, the last kinetic energy of the two objects is the same, and the speed of the wooden block is along the direction of the plank, and part of the energy of the ball is wasted to rotate around itself, so it should be the wooden block that arrives first. If it's a problem in life, it's not necessarily, it depends on the situation.

The key is to look at the smoothness, as far as the common board in life is concerned, it should be the ball that arrives first, and the angle is set at about 45 degrees.

According to the landlord's meaning of small friction, it should be the ball that comes first Because the gravitational potential energy of the ball is converted into the kinetic energy of the center of gravity of the ball and the rotational kinetic energy of the ball, and the moment of inertia of the ball is 2 5mr, that is, under the condition of obtaining the same energy, the rotational speed r of the surface of the ball surface point relative to the center of the sphere is greater than the motion speed of the cube, and they all slide down from the same height along the same slope with zero initial velocity, and the energy loss caused by friction is not considered, so the ball lands first.

The reality should be that the ball slides down first, and the ball has a higher velocity.

According to s=1 2*a*t*t

If the same inclined plane s is the same, it depends on the acceleration a, and the acceleration is the (downward component of gravity - friction) mass.

The downward component produced by gravity is the same, the mass is the same, and the frictional force is different.

The rolling friction of the sphere is less than the sliding friction of the cube, and the acceleration of the side sphere is larger, so it takes less time.

It depends on how smooth your planks are. If idealized, the friction is zero, and the sphere and the cube arrive at the same time because they have the same force along the inclined plane, the acceleration is the same, and the displacement is the same. If the degree of smoothness is not good and the friction force cannot be ignored, then the sliding friction is greater than the rolling friction, and the sphere reaches it first.

Look at what you mean by smooth planks or pieces of cardboard.

If smoothness means that there is no friction, then it is reached at the same time.

If friction is not ignored, then the ball comes first.

The reason for this is at least two things.

1. The rolling friction is less than the sliding friction. (This is why the car is equipped with wheels instead of sleds).

2. Objects with the same friction coefficient and small contact area of the same medium have small friction force. (That's why skates are based on skates instead of a chunk of metal).

The ball slides down first.

It is based on the principle of friction to calculate who will slide to the ground first.

The same medium, the friction coefficient is the same, the contact area between the sphere and the slide plate is small, and the resistance is small.

Therefore, the acceleration of the descent is much the same as 0 velocity and the starting velocity is the same distance.

The ball slides down first.

The sphere slides to the bottom first.

Because the rolling friction is small and the sliding friction is small.

They will arrive at the same time.

Because both are of the same quality, and they are both on smooth wooden boards.

Both are subject to the same gravitational and supporting forces, but are not subject to any other force, so their acceleration is the same.

And because the initial velocity is 0

In the end, because the two objects travel from the same starting point to the same end point, the distance is the same.

So arrive at the same time.

It should arrive at the same time.

First of all, they are at the same height, so their bits can be made the same. And because the acceleration due to gravity does not change. So the time it takes to slide down is the same.

If smoothness means that there is no friction, then it is reached at the same time.

The potential energy is the same) If the frictional force is not ignored, then the ball comes first.

The contact surface of the wooden block is larger than that of the wooden ball, so the friction is also large).

The sphere will fall first.

Because the sphere is rolling friction.

The cube is sliding friction.

The sliding friction is greater than the rolling friction, and it should be the ball that rolls down first!

Trust me, I'm a high school student!

Definitely a sphere, because the rolling friction is small with sliding friction.

If it is completely smooth, the sphere will not rotate.

So if it's completely smooth, both are equally to.

The sphere goes to the bottom first.

The principles have been summarized very well above, so I won't go into details.

Not necessarily! If the block is larger than the ball, there is a chance that the block will arrive before the ball!!

The question is complex.

Among them, it is not only the friction force, but also the acceleration of the rolling speed of the sphere to absorb a part of the potential energy.

Meantime. You can push a=g-sinbg yourself

b is the angle of inclination.

If nothing else, the sphere should have landed first! The reason is simple! Limit method: if your slope is not smooth enough, or not inclined enough, then the cube may not move, in other words, the landing time is infinite. But can you make the circle not roll?

1. Landing at the same time, because it has nothing to do with quality. The acceleration due to gravity in the vertical direction is the same.

2. The volume of the wood ball and the iron ball are the same, so the resistance of the two balls is the same at the same rate, but the mass of the iron ball is greater than the mass of the wood ball, so the influence of air resistance on the iron ball is less than the impact on the wood ball, so the falling acceleration of the iron ball is larger.

Because Zhao Song this iron ball first landed in front of the yard.

3. The volume is the same, the air resistance is the same, but the mass of the iron ball is large, so the reverse drag acceleration a=f m is small relative to the family mode, so the downward acceleration of the iron ball is large, and it falls first.

4. The wooden ball and the iron ball should land at the same time, and the landing time is only related to the height and gravitational acceleration, and the resistance is generally not remembered at this time. The impact on the resistance of the paper piece cannot be ignored.

Note to understand what it means to be free falling.

Free fall is defined as having zero initial velocity only due to gravity.

If you tie two balls together, logically speaking: h=1 2gt 2, they are landing at the same time, note that this is an experiment in a vacuum.

In real life, it will also be affected by air resistance, you see that the goose feathers fall down, very slowly, because the gravity is very small, greatly affected by air resistance, and the hammer is very heavy, it falls relatively quickly, and is less affected by air resistance, of course, it is also related to the area in contact with the air, so the iron head should be heavy, and the influence of air resistance is small, so it lands first.

Hope it helps!

Dear, it is also on the ground together, of course, if you put the iron head down, it must be the iron head that lands first, and you let go of the hammer flat, and it is landed together, don't you believe it? You can do the following experiments.