Sliding vs Rolling: Homework Analysis

[gigglin_horse]

Homework Statement

"Suppose the sloping surface was very slippery so no rolling occurs (the can slides). Would the can reach the bottom sooner or later compared with the rolling motion? Explain the difference"



I don't know if its relevant, but the slope was 4cm at the high end, and 1.5 meter long.

 

[glueball8]

What do you think?

 

[gigglin_horse]

I read somewhere that rolling has less translational KE, and that sliding makes it to the bottom first...
This makes me even more confused

 

[glueball8]

ya your right.

basically gravitational energy is converted into translational KE and rolling energy (for the rolling one)
so
$$mgh=\frac{1}{2}mv^2+\frac{1}{2}I \omega^2$$

what are you confused about?

 

[gigglin_horse]

Ohhhh ok.
Thats brilliant, thanks for your help