The laws of motion-a block pulled by a light cord

[haha1234]

Homework Statement

A block of mass 2.20 kg is accelerated across a rough surface by a light cord passing over a small pulley as shown in figure.The tension T in the cord is maintained at 10.0N,and the pulley is 0.100m above the top of the block.The coefficient of kinetic friction is 0.400m.
Determine the acceleration of the block when x=0.400.

Homework Equations

The Attempt at a Solution

Are there any mistake?
tanθ=0.4/0.1
θ=76.0°
F-f=ma
10sinθ-0.4x(2.2x9.8-0.1cosθ)2.2a

 

[NascentOxygen]

Are there any mistake?

It is a mistake to present a problem like this without an accompanying diagram, and a mistake to attempt to solve it without drawing a forces diagram to help you.

You also haven't indicated the tension in the cord.

http://imageshack.us/scaled/landing/109/holly1756.gif

 

[haha1234]

It is a mistake to present a problem like this without an accompanying diagram, and a mistake to attempt to solve it without drawing a forces diagram to help you.

You also haven't indicated the tension in the cord.

http://imageshack.us/scaled/landing/109/holly1756.gif

Sorry.:shy:

 

[NascentOxygen]

Okay, third mistake, you have attached the wrong pic!

 

[haha1234]

Okay, third mistake, you have attached the wrong pic!

Sorry again.

 

[tiny-tim]

hi haha1234!

what is this? …

(2.2x9.8-0.1cosθ)

 

[haha1234]

hi haha1234!

what is this? …

(2.2x9.8-0.1cosθ) is the normal force of the block.

 

[tiny-tim]

(2.2x9.8-0.1cosθ) is the normal force of the block.

but 0.1cosθ isn't a force, it's a distance

 

[haha1234]

but 0.1cosθ isn't a force, it's a distance

Oh,i have made a stupid mistake.
I can find the correct answer now.
Thank you!

 

[haha1234]

deleted

 

[Henry Jeong]

tanθ=0.1/0.4 <- check it.