# Recent content by Santilopez10

bump.
2. ### Falling rod against a wall

You missed a negative sign in the expression for ##\omega## which arises from the derivative of cosine.
3. ### Falling rod against a wall

Alright, but then why when using parametrization we get a negative answer?
4. ### Falling rod against a wall

$$a \hat j= \alpha \hat k \times (-0.33 \hat i + 0.33 \hat j) -6 \hat k \times (2 \hat i + 2 \hat j)$$ $$-6 \hat k \times (2 \hat i + 2 \hat j)= \begin{vmatrix} i & j & k \\ 0 & 0 & -6 \\ 2 & 2 & 0 \end{vmatrix} =6 \begin{vmatrix} i & j \\ 2 & 2 \end{vmatrix} = 12 \hat i -12 \hat j$$...
5. ### Falling rod against a wall

Seems like compared to your answer, the term that is giving me problems is ##\vec \omega \times \vec v_{A/B}##. If only ##\vec v_{A/B}## would be ## -2 \hat i + 2 \hat j## instead of ## 2 \hat i + 2 \hat j## then I could get the negative sign. To be honest I do not see where I committed a mistake.
6. ### Falling rod against a wall

I believe you missed the linear acceleration term that arises due to the quotient rule. Plus the derivative of 1/sin(x) is not 1/sin^2(x).