Recent content by Quarkn

Homework Statement find the derivative of: 4e^t((e^2t)-(e^t)) Homework Equations d/dx[b^x] = lnb(b^x)d/dx(x) The Attempt at a Solution I tried subtracting the two exponents in the brackets as well as multiplying it out. both wrong. Help?

Yes, you are correct. I guess i had some other weird method in my head :S Substitution works, sorry! Thanks!

Homework Statement (8x+1)^0.5 Homework Equations The Attempt at a Solution I tried using substitution but it clearly doesn't work because nothing in the brackets equals when derived. Anyone help me with the beginning steps?

Yes, it is 3.49 rad/s, sorry :P Anyways, I found out the answer. My problem was that I didn't know theta was used as the 2 revolutions.

Homework Statement A turntable must spin at 33.3RPM (3.49 rev/s) to play an old fashioned vinyl record. How much torque must the motor deliver if the turntable is to reach its final angular speed in 2 revolutions, starting from rest? The turntable is a uniform disk of diameter .305m and mass...

So would you find the volume of each spheres first? And if i set the two densities equal, wouldn't the masses just cancel? ex. D=M/V, M/v=M/V ?

Homework Statement A bowling ball made for a child has half the radius of an adult bowling ball. They are made of the same material (and therefore have the same mass per unit volume). By what factor is a) mass and b) rotational inertia if the child's ball reduced compared with the adult ball...