# Homework Help: 2 mp problems that I sorta understnad but dont?

1. Mar 1, 2005

### RhysticGenesis

2 mp problems that I sorta understnad but dont??

Edit: I figured out first problem... I was missing + pi/2 in the equation but still a little screwed up on second problem :

Edit: Figured both of em out with help. thanks for the help

Last edited: Mar 1, 2005
2. Mar 1, 2005

### Staff: Mentor

Check your answer for $\omega t = 90$ degrees and see if your signs are correct. Note: Positive $\omega$ means it rotates counter-clockwise!

Last edited: Mar 1, 2005
3. Mar 1, 2005

### RhysticGenesis

Yeah I just got it before I read your post guess I was little stupid on that one heh.. but second one I still dont get what im doing wrong?

4. Mar 1, 2005

### dextercioby

$$\theta (t)=\theta(0)+\omega_{0}t+\frac{1}{2}\alpha t^{2}$$
$$\omega (t)=\omega(0)+\alpha t$$

That's all u have to use...Properly.Pay attention to signs & initial conditions...

Daniel.

5. Mar 1, 2005

### RhysticGenesis

dont need help anymore heh got both answerss I needed I feel quite stupid now actually heh

6. Mar 1, 2005

### Staff: Mentor

OK.
Not clear what you did. Use $\omega_f = \omega_i + \alpha t$; be sure to use proper units for $\omega$.

Last edited: Mar 1, 2005