What is the expression for the velocity of the Car in Vector

Click For Summary

Homework Help Overview

The discussion revolves around determining the expression for the velocity of a car in vector form. Participants are exploring the context of motion in one direction and the implications of vector representation in physics.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the initial attempt at expressing velocity as a vector, questioning the clarity of the problem statement regarding units and whether it seeks a velocity or position vector. There is also consideration of the relationship between speed and unit vectors.

Discussion Status

The discussion is ongoing, with participants providing insights and clarifications. Some have offered alternative expressions and raised questions about the variables involved, indicating a productive exploration of the topic.

Contextual Notes

There are noted ambiguities in the problem, such as the required units and the distinction between velocity and position vector expressions. Additionally, a visual aid was mentioned as potentially relevant to the discussion.

Lapse
Messages
49
Reaction score
4

Homework Statement


upload_2019-2-10_20-45-49.png


Homework Equations


v = I + j + k
v = d/t

The Attempt at a Solution



I thought the answer was as simple as: v = 63i + 0j + 0k, since the car only has motion in one direction...
...but I got it wrong, so clearly I'm missing something here.
 

Attachments

  • upload_2019-2-10_20-43-14.png
    upload_2019-2-10_20-43-14.png
    14.1 KB · Views: 504
  • upload_2019-2-10_20-45-49.png
    upload_2019-2-10_20-45-49.png
    14.1 KB · Views: 1,079
Physics news on Phys.org
The question is somewhat vague. I see two aspects that are unclear.
What units are to be used in the answer?
Does it want an expression for velocity or one for location?
 
  • Like
Likes   Reactions: Delta2
I think the problem wants the expression for the position vector too, that is ##\vec{r}=r_i\cdot i +0j+0k##. What is ##r_i## here?
 
Whoops. Sorry, I should've had this picture there too:

upload_2019-2-10_22-54-36.png
 

Attachments

  • upload_2019-2-10_22-54-36.png
    upload_2019-2-10_22-54-36.png
    12 KB · Views: 972
it says using the speed v and the unit vectors i,j,k

maybe try ##v\cdot \vec{i} +0\cdot\vec{j}+0\cdot\vec{k}##
 
  • Like
Likes   Reactions: Lapse
Thanks. I knew it was something silly.
 
  • Like
Likes   Reactions: Delta2

Similar threads

Replies
2
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
Replies
26
Views
4K
  • · Replies 29 ·
Replies
29
Views
4K
Replies
1
Views
886
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
7K