# How Do You Calculate Instantaneous Velocity at Point 2?

• deficiency4math
In summary, the conversation is about finding the instantaneous velocity for point 2 given 3 points with different distances and time intervals. The motion is described as variable acceleration, with the velocity increasing by one each time. The suggested method is to find the average acceleration and use it to calculate the velocity at a specific time.
deficiency4math
Hi,

I was wondering how to solve the instantaneous velocity for this.

I have 3 points which have 5 cm between point 1 and point 2 and 9 cm between point 2 and point 3 (this is easy, i just need to grasp the concept)

The question is "What is the instantaneous velocity for point 2?

How would I figure this out?

thanks

Do you have any times?

oh, yes, sorry,

the time intervals between the points are 1/40th of a second (lets say)

(sorry, I forgot to post them... I kinda forgot!)

Can you give a little background? What kind of motion is going on here, constant acceleration?

it would be variable acceleration, because the consecutive distance between 1&2 is 5 and 2&3 9... so let's say that each time, the velocity increases by one.

Would I just take the velocity of 1-2 (5cm per 1/40th of a second) and 2-3 (9cm per 1/40th of a second) and find the average of them to get the instantaneous?

deficiency4math said:
it would be variable acceleration, because the consecutive distance between 1&2 is 5 and 2&3 9... so let's say that each time, the velocity increases by one.

Define acceleration in terms of velocity. Does acceleration have to change for velocity to change?

Would I just take the velocity of 1-2 (5cm per 1/40th of a second) and 2-3 (9cm per 1/40th of a second) and find the average of them to get the instantaneous?

I don't know how accurate you need to be, but what I would do is try to figure out the average acceleration. The object is speeding up, so its position function is:

$$x(t) = x_0 + v_0t + 1/2 * at^2$$

We traveled x(t) = 14cm in t=0.05sec. Can you find the acceleration? Can you find the velocity at t=0.025 with this?

## 1. What is instantaneous velocity?

Instantaneous velocity is the rate of change of an object's position at a specific moment in time. It is the speed and direction of an object at a particular instant.

## 2. How is instantaneous velocity different from average velocity?

Average velocity is the total displacement of an object divided by the total time taken, while instantaneous velocity is the velocity at a specific point in time. Average velocity gives an overall picture of an object's motion, while instantaneous velocity provides information about an object's motion at a single moment.

## 3. Can instantaneous velocity be negative?

Yes, instantaneous velocity can be negative. This indicates that the object is moving in the opposite direction of its reference point or initial position. For example, if an object is traveling east and then turns around and starts moving west, its instantaneous velocity will be negative.

## 4. How is instantaneous velocity calculated?

Instantaneous velocity is calculated by finding the slope of the tangent line to the position-time graph at a specific point. This can be done by taking the derivative of the position function with respect to time.

## 5. Why is instantaneous velocity important in physics?

Instantaneous velocity is important in physics because it provides information about an object's motion at a specific moment, allowing us to analyze and understand the object's behavior. It is also used in many equations and laws, such as Newton's second law of motion and the kinematic equations.

• Introductory Physics Homework Help
Replies
5
Views
1K
• Introductory Physics Homework Help
Replies
5
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
366
• Introductory Physics Homework Help
Replies
7
Views
2K
• Special and General Relativity
Replies
11
Views
1K
• Introductory Physics Homework Help
Replies
40
Views
2K
• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
5
Views
2K
• Introductory Physics Homework Help
Replies
11
Views
856