Question about notation in physics

  • Thread starter Thread starter monac
  • Start date Start date
  • Tags Tags
    Notation Physics
AI Thread Summary
The discussion centers on finding the velocity and position of a particle with an initial velocity of 5i m/s and a varying acceleration of a = 6√t j. The participant integrated the acceleration to determine velocity and then integrated the velocity to find position. There is a question about whether to include the vector notation (arrow) when expressing these equations as functions of time. It is confirmed that vector notation should be used, and the inclusion of unit vectors i and j is necessary for clarity. The final conclusion emphasizes that both sides of the equation must maintain vector representation.
monac
Messages
20
Reaction score
0
So it says that a particle is going with a velocity of 5i m/s at t = 0 and varying acceleration a = 6√t j.
it asked me to find the velocity and position of the particle as a function of time.
So i did an integral of the acceleration to get velocity and did the integral of the velocity to get the position. I was wondering whenever i write the equation as a function of time, do i still need that arrow (→ ) on top of the v for vector and r for position?
 
Physics news on Phys.org
monac said:
So it says that a particle is going with a velocity of 5i m/s at t = 0 and varying acceleration a = 6√t j.
it asked me to find the velocity and position of the particle as a function of time.
So i did an integral of the acceleration to get velocity and did the integral of the velocity to get the position. I was wondering whenever i write the equation as a function of time, do i still need that arrow (→ ) on top of the v for vector and r for position?
If it's a vector, then yes, we usually put the arrow above the variable.

\vec{r}(t) = x(t)\hat{i}+t(t)\hat{j}+z(t)\hat{k}
 
SammyS said:
If it's a vector, then yes, we usually put the arrow above the variable.

\vec{r}(t) = x(t)\hat{i}+t(t)\hat{j}+z(t)\hat{k}

so if I solved the integral and I got like
r(t) = 8t^2 + 5t
I put the arrow on top of the arrow since it's a vector. I get that ...
But do I still include the i and j?
so would it be r(t) = 8t^2 i + 5t j ?
 
monac said:
so if I solved the integral and I got like
r(t) = 8t^2 + 5t
I put the arrow on top of the arrow since it's a vector. I get that ...
But do I still include the i and j?
so would it be r(t) = 8t^2 i + 5t j ?
Yes, use the \hat{i} & \hat{j}\,.

If the left side of an equation is a vector, then the right side must also be a vector.
 
Thank you! :)
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top