Find Speed of Particle: Position Function r(t)= et(cos(t)i+sin(t)j+7tk)

  • Thread starter Thread starter julz3216
  • Start date Start date
  • Tags Tags
    Particle Speed
julz3216
Messages
18
Reaction score
0

Homework Statement



Consider the following position function.
r(t)= et(cos(t)i+sin(t)j+7tk)

Find the speed of a particle with the given position function.


Homework Equations



I know I take the derivative of the function but I can't seem to get speed.
I got v=e^t(cos(t)i+sin(t)j+7(t)k)+ e^t(-sin(t)i+cos(t)j+7k)

The Attempt at a Solution



I just can't find the speed, i think i may be just slightly off. I currently have speed is 7e^t(t+1) which is wrong.
 
Physics news on Phys.org
Edit:

You are simply using "k" part, where is your i and j part. They don't cancel out.
 
Last edited:

Thread 'Prove that the integral is equal to ##\pi^2/8##'

Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
View full post »

Similar threads

Unit tangent vector of r(t) = (e^t)(cos t ) i + (e^t)(sin t
Replies
3
Views
2K
Find y(t) for, x(t) = sin t and TF of a block is 1/(s+1)
Replies
5
Views
2K
Curvature of r(t) = (3 sin t) i + (3 cos t) j + 4t k
Replies
22
Views
7K
Limiting Value of a Vector Function
Replies
13
Views
2K
How to write the complex exponential in terms of sine/cosine?
Replies
7
Views
5K
How do I find the speed of an object with a given position function?
Replies
2
Views
986
Find FT of Function: Solution & Explanation
Replies
3
Views
1K
Find the unit normal vector of r(t)
Replies
7
Views
2K
How to Find the Maximum and Minimum Speed of a Particle?
Replies
2
Views
1K
Line integral convert to polar coordinates
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top