Help Quickly: Solve Coefficient of Kinetic Friction Problem

[Port]

Help quickly please

I need help on this and quick!:
A 4kg block is pushed alomng the ceiling with a constant apllied force of 85N that acts at an angle of 55 degrees with the horizontal. The block accelerates to the right at 6m/s^2. detremine the coefficient of kinetic friction between the block and the ceiling.

ok i worked out the problem but i got the wrong answer. the values i got are: for normal force=69.62N. for ap=12.19. for af=6.19. for Ff=24.8N final answer=.356 and i need .816 what did i do wrong?

 

[dextercioby]

Check the numbers in the text of the problem.That block should be flying...

Daniel.

 

[Port]

what do u mean the numbers in the problem are right?

 

[dextercioby]

what do u mean the numbers in the problem are right?

1.U double posted.Two threads on the same problem.It's not fair...
2.Yes,by the looks of it,the normal force should be zero and the body should raise from the ground...

Daniel.

 

[Yapper]

Dex, its being pushed agaisnt the ceiling...

 

[Port]

wait but why if someone is pushing it on the ceiling? ur confusing me!

 

[Yapper]

OOHHHH I know, we forgot to account gravity, get the normal force, subtract or add gravity, I am to tired to think, and then divide by Ff! see which one works

 

[dextercioby]

Dex, its being pushed agaisnt the ceiling...

Sorry,didn't read that part. You're right...It doesn't fly away...

Daniel.

 

[Port]

wait what? how do i add or subtract gravity?

 

[learningphysics]

Read the other thread Port.