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

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
5 replies · 4K views
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: 527
  • upload_2019-2-10_20-45-49.png
    upload_2019-2-10_20-45-49.png
    14.1 KB · Views: 1,101
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: 994
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