Find the friction force impeding its motion.

[nickrace09]

Ok, our teacher is pretty much insane and doesn't teach anything at all. I'm sure this problem is incredibly simple, but I'm just not sure how to do it.

Original Problem: A 15.0 kg box is released on a 32 degree incline and accelerates down the incline at .30m/s/s. Find the friction force impeding its motion. What is the coefficient of kinetic friction?

What I Did: I found Normal Force to be 127 N with Wcos(theta) but I don't know where to go from there. Any help would be much appreciated.

 

[ownedbyphysics]

Ok, our teacher is pretty much insane and doesn't teach anything at all. I'm sure this problem is incredibly simple, but I'm just not sure how to do it.

Original Problem: A 15.0 kg box is released on a 32 degree incline and accelerates down the incline at .30m/s/s. Find the friction force impeding its motion. What is the coefficient of kinetic friction?

What I Did: I found Normal Force to be 127 N with Wcos(theta) but I don't know where to go from there. Any help would be much appreciated.

my teacher doesn't teach us anything either...except this ma=mgsin(theta)-umgcos(theta) then you can use that to solve for coefficient of kinetic friction and friction force. I think.

 

[nickrace09]

thanks dude that works