# In the circular motion below, what will be the velocity?

## Homework Statement

In circular motion what will be the change in velocity if initial velocity and final velocity is 2 m/s? From the left, in the 3rd diagram, if initial velocity and final velocity is 2 m/ s then what is the change in velocity? t = 5 s

## The Attempt at a Solution

Acceleration = Vf - Vi / t = (-2i) - 2i / 5 = -4i / 5 = -0.8 m/s^2 but the answer is 0.8m/s^2.

#### Attachments

• circular-motion-2-1024.jpg
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jbriggs444
Homework Helper
I see two illegible drawings (pure black) and something in the middle with some semi-legible chicken scratchings.

I think you should re-state the problem and provide readable drawing, it is not clear to me. Hint: velocity is a vector, giving value like "2 m/s" is not sufficient.

Delta2

## Homework Statement

In circular motion what will be the change in velocity if initial velocity and final velocity is 2 m/s? From the left, in the 3rd diagram, if initial velocity and final velocity is 2 m/ s then what is the change in velocity? t = 5 s

## The Attempt at a Solution

Acceleration = Vf - Vi / t = (-2i) - 2i / 5 = -4i / 5 = -0.8 m/s^2 but the answer is 0.8m/s^2.
I have edited the image so that you can understand. Please see the image and let me know.

#### Attachments

• circular-motion-2-1024.jpg
43.9 KB · Views: 210
jbriggs444
Homework Helper
In circular motion what will be the change in velocity if initial velocity and final velocity is 2 m/s?
Acceleration = Vf - Vi / t = (-2i) - 2i / 5 = -4i / 5 = -0.8 m/s^2 but the answer is 0.8m/s^2.
The question asks for a change in velocity but the answer is an acceleration? That's wrong.

SammyS
(-2i) - 2i

How can both velocity vectors have same unit vector?

According to your drawing the first one, one is along j and another along i.

The pictures are still not clear. What are you using?

The question asks for a change in velocity but the answer is an acceleration? That's wrong.
Yes, my question is that in the picture change in velocity is 4 or -4, As I know the change in velocity is Vf -Vi = (-2i) - 2i = -4i. please see the picture.

#### Attachments

• circular-motion-2-1024.jpg
43.9 KB · Views: 196
How can both velocity vectors have same unit vector?

According to your drawing the first one, one is along j and another along i.

The pictures are still not clear. What are you using?
Could you suggest an online editor where I could sharpen my image as much clear as I can?

jbriggs444
Homework Helper
Yes, my question is that in the picture change in velocity is 4 or -4, As I know the change in velocity is Vf -Vi = (-2i) - 2i = -4i. please see the picture.
I would say that the change in velocity is neither 4 nor -4. It is -4i.

HCverma
I would say that the change in velocity is neither 4 nor -4. It is -4i.
would you please let me know whether you could understand my edited image I provided so that in future I would edit my images to that degree. Is it readable?

#### Attachments

• circular-motion-2-1024.jpg
43.9 KB · Views: 203
jbriggs444
Homework Helper
would you please let me know whether you could understand my edited image I provided so that in future I would edit my images to that degree. Is it readable?
It is not pretty, but it is magnified enough that I can read it.

HCverma
It is not pretty, but it is magnified enough that I can read it.

haruspex
Homework Helper
Gold Member
2020 Award
I would say that the change in velocity is neither 4 nor -4. It is -4i.
It is not clear to me whether the use of complex variables to represent the vectors comes from the original problem or has been introduced by the student.
@HCverma , please state the problem as given to you, word for word.

HCverma
It is not clear to me whether the use of complex variables to represent the vectors comes from the original problem or has been introduced by the student.
@HCverma , please state the problem as given to you, word for word.
Next time I will.

haruspex