Recent content by Zeno's Paradox

Is this true? \vec \omega \times r = \vec v

Read please example 2 of http://cnx.org/content/m14060/latest/ . P1 P2 On picture 2 there are those two tension labeled by T which are equal. Why equal? And shouldn't they exert just torque? I know we are considering the pulley to be massless, so no torques. So is it correct to...

\tau = rF \sin \theta sin \theta = \sin (\pi - \theta) :smile:

This might help: http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html#tra14 \frac{h}{R} = \frac{\tan \theta}{4} = 1/2 Then, you may find theta. Note: You should not memorize this formula, but understand how to deduce it.

You have data to calculate the center of mass before the people move. Since, there are no external forces acting on the c.m., will he change? So, x_{cm}_{i} = x_{cm}_{f}

Check the units of (48 kg) / (10 m/s^2). Compare this units to Newtons. Also, why are you converting mass to weight? :smile:

I think I will land somewhere backwards, there's no force acting on me so the train during that time is traveling faster than me. But I could be wrong, that is why I asked. :wink:

But if the train is accelerating, when I am in the air after jumping, will I land in the same place?

Your suggestions were very useful. We were able to get 1.7 volts, but instead of NaOH we used KOH. Is there an optimum KOH concentration ?

Yes, you did it correctly. Remember that you could calculate the displacement averaging out the velocity only because the acceleration is constant. The other formula would be: d = (1/2)at2. Check that the solution is the same. Try to show that v(average)*t = (1/2)at2

Visual1Up, I think you know how to derive the formula that gives range in function of \theta , v_o, which is: R = (v_0^2 \sin 2\theta)/g Then, it's easy. :smile:

Is there the notion of time in a motionless world? I just feel time because things change. Is this a wrong idea? What's your opinion?

May I ask a stupid question regarding this. In hot days, the particles of the air are vibrating more, so shouldn't we hear a sound?

Thanks for all your help. :)

And Nickel-Chromium works better or worse than just nickel?