Exploring Velocity: Questions & Answers

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In summary, the conversation discusses the relationship between car tire speed and forces, the concept of average velocity, determining constant speed or velocity, converting between units, and the difference between positive and negative acceleration. The conversation also encourages critical thinking and problem-solving.
  • #1
king_2005
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1. why are car tires moving at 30 m/s experience four times greater forces than when moving at 15 m/s (or half the speed)?
2. What is meant by average velocity?
3. How can you tell if the speed or velocity is constant?
4. How do you change from one unit to another?
5. what is the difference between positive and negative acceleration?
 
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  • #2
It would be a shame to just give you the answers. You'd learn a lot more if you think about the problems. Post what you think is correct... and we can check.

:wink:
 
  • #3
1. the car tires in 30 m/s experienced greater force because of its motion. It is moving fast than in 15 m/s.
2. average velocity could be expressed as: velocity/2
3. if the time traveled is the same
4. by using some conversion tables,then you can change into another unit
5. I have no idea

Hope my answers are correct..
 
  • #4
king_2005 said:
1. the car tires in 30 m/s experienced greater force because of its motion. It is moving fast than in 15 m/s.
Yes, but why exactly 4 times greater ? Do you know any formulas involving velocity and force on rotating objects ?
 
  • #5
king_2005 said:
2. Average velocity could be expressed as: velocity/2
3. If the time traveled is the same
4. by using some conversion tables,then you can change into another unit
5. I have no idea
2. the average velocity is described as the change in position over the change in time. For example, if you went 10 meters in 10 seconds, the average velocity is 1 m/s. This does not mean that at every point in between t = 0 and t = 10 that you had a velocity of 1 m/s, it just means that on average your velocity was 10 meters / second.

3. If your speed/velocity is constant, you are not accelerating. Which means that the net force acting on you is zero.
You might also say that if the distance traveled in one interval of time is equal to the distance travel in another interval of the same length of time, then the average velocity is the same.
 
  • #6
What if you consider the tyre to rotate about the point of contact with the road and calculate the centripetal acceleration of the middle of the tyre with respect to this point?
 
  • #7
5. The sign is used to indicate direction of the component. When one attempts such one dimensional (motion in aline) problems, you choose a coordinate system (direction of positive motion or x-axis or y-axis). Positive kinematic quantities therefore points in the one way, while negative quantites are in the opposite direction. If the velocity is positive and the acceleration is negative (or the other way round), the object is decelerating. If both velocity and acceleration have the same signs, then the object is accelerating.
 

1. What is velocity?

Velocity is a measure of the speed and direction of an object's motion. It is calculated as the rate of change of an object's position over time, and is typically measured in units of distance per time (e.g. meters per second).

2. How is velocity different from speed?

While velocity and speed are often used interchangeably, they are actually different concepts. While speed only measures how fast an object is moving, velocity includes the direction of motion as well. This means that an object can have the same speed but different velocities if they are moving in different directions.

3. What factors can affect an object's velocity?

An object's velocity can be affected by various factors, such as its mass, the forces acting upon it, and the surface it is moving on. These factors can change the object's speed, direction, or both.

4. How is velocity measured?

Velocity can be measured using different tools, depending on the object and its motion. For example, a stopwatch and a ruler can be used to measure the velocity of an object in a straight line. In more complex cases, such as curved or changing motion, advanced equipment like radar or laser sensors may be used.

5. What is the difference between average and instantaneous velocity?

Average velocity is the total displacement of an object over a certain time period, divided by the time taken. It gives an overall measure of an object's motion. On the other hand, instantaneous velocity is the velocity of an object at a specific moment in time, and is calculated by taking the limit of the average velocity as the time interval approaches zero. In simpler terms, average velocity is like looking at a movie in slow motion, while instantaneous velocity is like looking at a snapshot of a particular moment in the movie.

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