Direction of concurrent velocity and acceleration

In summary, the conversation discusses the velocity and acceleration of two points constrained to vertical motion. Point A is moving upwards with a velocity of 1m/s and decelerating at a rate of 4m/s2, while Point B is moving downwards with a velocity of 2m/s and accelerating at a rate of 5m/s2. The speaker is trying to interpret this information and is unsure about the direction of the acceleration vectors. The problem statement is considered to be poorly stated, as it does not clearly mention the direction of the positive acceleration.
  • #1
Sirsh
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I have a problem in one my dynamics classes, I have a the velocity and accelerations of two points that are constrained to vertical motion.

Point A has a velocity of 1m/s upwards and is decelerating at a rate of 4m/s2 and point B has a velocity of 2m/s downwards and is accelerating at 5m/s2.

Now, I need to draw these in vector form. So I am trying to interpret this information as it is quite confusing to me.

A obviously has a velocity vector straight upwards, but the acceleration vector which is decelerating, is this pointing downwards?

B's velocity vector is downwards, and it is said to be accelerating, so I'm assuming that this means that it is accelerating in the direction of the velocity vector, so also downwards.

Is this the correct way to interpret this situation?

Thanks!
 
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  • #2
Sirsh said:
point B has a velocity of 2m/s downwards and is accelerating at 5m/s2.
Your interpretation is probably correct, but I agree it is confusing. If it had said the velocity is -2m/s and the acceleration is +5m/s2 I would say it is getting slower. If it had said the velocity is 2m/s down and it is getting faster at 5m/s2 then it is accelerating downwards. But saying that it is accelerating at 5m/s2 without making clear which way is positive is somewhat ambiguous.
 
  • #3
The problem is stated poorly. Let's assume that all the pertinent information is stated. Then point A is traveling upward and is decelerating or slowing. In 0.25 seconds the velocity will reach zero. Velocity points up, acceleration points down. Point B is less ambiguous, both vectors point down.

Best I can do.
 

FAQ: Direction of concurrent velocity and acceleration

1. What is the relationship between velocity and acceleration?

The relationship between velocity and acceleration is that acceleration is the rate of change of velocity over time. In other words, acceleration measures how quickly the velocity of an object is changing. If an object is accelerating, its velocity is changing by a certain amount every second.

2. Can an object have a constant velocity and changing acceleration?

Yes, an object can have a constant velocity and changing acceleration as long as the direction of the velocity and acceleration vectors are the same. This means that the object is moving at a constant speed in a straight line, but the direction of its velocity is changing.

3. How do you calculate the direction of concurrent velocity and acceleration?

The direction of concurrent velocity and acceleration can be calculated using trigonometry. First, find the angle between the velocity and acceleration vectors. Then, use the cosine function to find the angle between the velocity vector and the horizontal axis. This will give you the direction of the velocity vector.

4. What is the difference between average velocity and average acceleration?

The difference between average velocity and average acceleration is that average velocity measures the change in an object's position over time, while average acceleration measures the change in an object's velocity over time. In other words, average velocity tells us how far an object has traveled, while average acceleration tells us how quickly its velocity has changed.

5. How does the direction of velocity and acceleration affect an object's motion?

The direction of velocity and acceleration can greatly affect an object's motion. If they are in the same direction, the object will speed up. If they are in opposite directions, the object will slow down. If the velocity and acceleration are perpendicular, the object will change direction but maintain a constant speed. The combination of velocity and acceleration determines the overall motion of an object.

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