The problem of acceleration is a bit confused, ask for help

If you don't have brakes. Turn it upside down!

The positive or negative of velocity acceleration is the meaning of direction, which is expressed like that for the sake of calculation.

The statement of uniform deceleration motion is unscientific, all linear motion with constant acceleration is called uniform acceleration linear motion, and uniform deceleration motion is a folk name.

Moreover, the change of velocity from 0 to negative is a phenomenon of increasing velocity, and negative refers to the direction, and there is no physical quantity smaller than 0 in the practical problem.

2.The acceleration is east, but the initial velocity of the car is not given, the initial velocity is west of course to the west, the acceleration is opposite to the direction of the velocity, the deceleration process

3.The two moments only give the speed size, not the direction.

If the direction of the front and rear velocity is the same, then the uniform acceleration linear motion with acceleration 6

If the front and rear velocity directions are opposite, then decrease from 4 to 0 and then increase from 0 to 10, the acceleration is 14, and the direction of acceleration is opposite to the direction of the initial velocity.

1. Tell you clearly, as long as the direction of acceleration remains the same, it must be reversed, and the direction is uniformly accelerated.

2. The car decelerates westward, such as braking.

3. Not necessarily, the acceleration is not necessarily in the same straight line as the initial velocity, and the second floor is quite correct.

1. When the velocity is reduced to zero, if the acceleration is still unchanged, the car will drive in reverse, and do a uniform acceleration motion to the west, and the direction of motion of the object should be the same as the direction of the acceleration of the object, because there is acceleration and the acceleration is unchanged, so it is a uniform acceleration motion.

2 brakes. 3.Not necessarily.

It can be evenly decelerated first and then accelerated, and the initial velocity and the end velocity are in opposite directions.

1. According to the actual situation, if the car steps on the brakes to slow down, it will stop after the speed is zero and will not go backwards. If you put the reverse gear in gear and press the accelerator pedal to slow down, the speed will be zero and then continue backwards.

The statement of uniform deceleration motion is unscientific, all linear motion with constant acceleration is called uniform acceleration linear motion, and the velocity changes from 0 to negative, which belongs to the phenomenon of increasing velocity, and negative refers to the direction.

2.The initial velocity is to the west, and the velocity value decreases.

3.The acceleration is in the opposite direction of the velocity, making a motion with an acceleration of -14m s.

In fact, the landlord did not figure out what is called uniform acceleration and uniform deceleration, where the uniform means that the acceleration does not change, and the addition and subtraction represent the increase and decrease of speed. Understand, but that's fine.

Tell you clearly"Late night snack"The answer is the correct answer. It's okay to divide it among me.

1 will open in the opposite direction is a uniform acceleration because it is added from the velocity zero and the direction of the acceleration is not the same.

2 Yes, the car is moving westward and the car itself is driving westward.

3 Not necessarily, it may be that the combined velocity of the uniform acceleration curve motion is 10m s type flat throwing motion.

The change in direction of acceleration is not a matter of turning it backwards and opening it forward.

The acceleration and motion in the same direction are accelerated motion, and the opposite is deceleration.

It's the same as above, which is to slow down and drive west.

If it is a uniform speed change, it must be.

1.If the acceleration really stays the same, for example, if someone pushes it, the car goes backwards. When discussing uniform acceleration and deceleration, the situation when the speed is 0 is not considered, in other words, when you say that the car is uniform acceleration and deceleration, the speed direction of the car will not change.

It can be said that at first it decelerates evenly, and then it accelerates evenly.

2.Yes, for example, the car is moving at a certain speed at a constant speed, and suddenly the engine turns off, at this time there is only friction, so the acceleration is in the opposite direction of the velocity, and the acceleration remains the same, this situation occurs, 3Not necessarily, for example, a small wooden block slides on a horizontal frictionless tabletop, assuming that the mass is 1kg, then give him a reverse force of 14n, then do a uniform deceleration in the first period of time, and then do a uniform acceleration.

p=f(vehicle power)*v

Constant p starts with a gradual increase in V, a gradual decrease in F, and a in a gradual decrease. The final f = friction and v max is p friction.

Constant A starts, f is constant, p increases at a constant velocity, and when it increases to p=p maximum, the same constant p

Which one depends on the parameters, how much rated power, how much acceleration, it depends on the specific question, (first floor) binghe2402 answer will help you encounter this kind of problem after the analysis.

The speed at the rated power is to start with the maximum traction The starting speed is of course fast, the constant is not to start with the maximum traction but to a certain traction force for a period of time, and the traction force will drop after reaching the rated power.

Fast at rated power.

p=f*v；f=m*a+f；v=a*t；Thereupon.

p=（m*a+f）*a*t；As t increases, a decreases. But at least at this time it is the maximum acceleration that can be provided, and if the acceleration is constant, it is only a non-maximum, otherwise the engine power cannot keep up and cannot be provided. The maximum acceleration at all times is naturally faster.

I've always been a physics class representative in high school, and trust me, that's right.

According to p=f*v

When p is constant, as your speed increases (there is a certain acceleration), f should decrease, where f is the traction force, f decreases the drag is unchanged, then the acceleration should decrease. Do acceleration motion with reduced acceleration. As f decreases to the same as the resistance, the velocity does not change, which is the maximum velocity, and the velocity decreases at a constant speed.

When the acceleration (a) is certain, as your speed increases, p should increase, at this time do a uniform acceleration motion (because a must be), when p reaches the rated power, the velocity will increase again, f will decrease, (similar to the above) do an acceleration motion with a decrease in acceleration, when f = resistance, the speed will go down.

If you don't understand yet, you can ask me. ^

Can you tell me, which reference book has it? I'm also worried about this.

To know the specific power and acceleration values, it is related to friction.

Whether it is caused by physical weakness, if the condition has been delayed for a long time, it is a difficult disease.

Beijing specializes in intractable diseases, is a well-known hospital in the country, you can go to the best to ask experts for diagnosis, but it is not very good.

If you can't find the problem, it is recommended that you go to the hospital for a check-up. You can't think of it. Don't delay.

The velocity of the cannon spark out of the barrel is v then v 2-0 = 2gh So v = 20 pieces of 5 pieces The acceleration of the fire is a = v t = 1000 pieces of 5

The average thrust of gunpowder against firecrackers f-mg=ma

So f = (20 + 2000 root number 5) n

h=1/2at^2

a=2h/(t^2)=500000m/s^2ma=f-mg

f=m(a+g)=1000020n

Answer: The average thrust of gunpowder against firecrackers is 1000020N

There are two types of dizziness in the elevator:

1. Dizziness during upward acceleration, because the human body accelerates upward, the blood falls in the body, and the head is ischemia, which is related to the acceleration of the elevator and cannot be solved on Mars.

2. Dizziness during downward acceleration, in a partial state of always, feeling dizzy because the body is not adaptable, this situation is related to the earth's gravitational acceleration, if the gravitational acceleration decreases, it will be reduced.

The amount of velocity change divided by the amount of time change.

The amount of change in velocity is greater than the amount of change in time.

The end velocity minus the initial velocity is divided by the time.

is the ratio of the amount of velocity change to the time it takes for this change to occur δv δt, which is a physical quantity that describes how quickly an object's velocity changes.

Acceleration a = δv δt

v The amount of change in velocity.

t The time taken for this change to occur.

Refers to the physical quantity of how fast or slow the velocity changes.

Acceleration is the ratio of the amount of velocity change to the time it takes for this change to occur δv δt, and is a physical quantity that describes how quickly an object's velocity changes.