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dks2114
Oct 8, 2007, 06:00 PM
A 50g ice cube can slide w/o friction up and down a 30 degree slope. The ice cube is pressed against a spring at the bottom of the slope, compressing the spring 10 cm. The spring constant is 25N/m. When the ice is released, what total d will ti travel up the slope before reversing direction?

W = (Ff + Fp ) d
But since No friction in this problem Ff=0
W= EPE

Giving us:
1250 = (0.245)d
d=5102m



Part 2 asks this: Let's say that the ice cube is replaces by a plastic cube whose coefficient of friction is .20. How far will the plastic cube travel up up the slope?

W = (Ff + Fp ) d
Plug in Ff
W= EPE

Giving us:
1250 = (.049 + .245) d
d= 4252m

Are these correct or did I miss something?

ebaines
Oct 9, 2007, 08:41 AM
Check your units - you're off by a factor of 10^6 in the first problem. Perhaps you may figured the spring is compressed 10 m, rather than 10 cm?

dks2114
Oct 9, 2007, 10:13 AM
That's exactly what I did... thank you!