A man drags a 130 lb crate across a floor by pulling on a rope inclined at 20.0 degrees with the horizontal. If the coefficient of static friction is 0.550 , and the coefficient of kinetic friction is 0.350, find the acceleration (in feet/second^2) of the crate at the instant it breaks loose and starts sliding.

I got an answer of 1.96 m/s^2 and then converted it to feet/sec^2 but it was wrong.

I did m*g, and then
fs=UFn,
fk=UFn

and finally did A=fx-fK/m, but that was the wrong answer/way. Any help would be super appreciated.

Question

A man drags a 130 lb crate across a floor by pulling on a rope inclined at 20.0 degrees with the horizontal. If the coefficient of static friction is 0.550 , and the coefficient of kinetic friction is 0.350, find the acceleration (in feet/second^2) of the crate at the instant it breaks loose and starts sliding.

I got an answer of 1.96 m/s^2 and then converted it to feet/sec^2 but it was wrong.

I did m*g, and then
fs=UFn,
fk=UFn

and finally did A=fx-fK/m, but that was the wrong answer/way. Any help would be super appreciated.

noelgreco · Answer

Did you convert from pounds to Newtons?

noelgreco · Answer

1.96 m/s^2 is correct.  6.45 ft/s^2 should be the conversion.