# A Rolling Disk

**1. The problem statement, all variables and given/known data**

A solid, Uniform disk of radius 5.00 cm and mass 1.50 kg is rolling without slipping a long a horizontal surface. The disk makes 2.00 revolution per second

a. Find the total kinetic energy (translational + rotational) of the disk

b. Find the minimum height h of the step (placed in front of the rolling disk) that will prevent the disk from rolling past it. (Hint: assume that the hight h is adjusted so that the disk rolls just up to the top of the step and stops. Conserve Energy)

**2. Relevant equations**

W= 2.00 Revolution x 2pi radian

V = wr

I = (1/2)mr^2

KE_rot = (1/2)Iw^2

KE = (1/2)mv^2

**3. The attempt at a solution**

a. I assumed that K_total = KE_rot + KE

K_total = 4.46 x 10^-3 Joules

b. I have no Idea how to solve this….help?

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