Calculating Force and Motion on an Inclined Plane

[ehild]

Well, OK. So -Fk+F = 456.837 N. What is Fk?

ehild

 

[Femme_physics]

Fk is 1.879 [kN]

Which means that I'm an idiot

Because I didn't translate KiloNewtons to Newtons heh

You got me

Thanks

 

[ehild]

There were fewer mistakes in your posts if you typed in the calculations. And they were easier to read.

ehild

 

[Femme_physics]

Still off, if I convert everything to Newton it turns out 1420.28 [N] whereas the manual says 4840.87 [N]

Can you help and tell me what did I miss?

 

[ehild]

It seems to me that you ignored a force. Maybe it is there, but I can hardly read your webcam picture. Would you please type in the solution, as everybody else do? ehild

 

[I like Serena]

As far as I can tell, you have the right answer.

Are you sure all the problem data correct?
Like that you have an initial speed of 6 m/s decreasing to 3 m/s?

 

[Femme_physics]

I will write the full question for reference

http://img846.imageshack.us/img846/6564/samemethod.jpg



An body whose weight is W proceeds upwards on an incluned plane, slanted to the horizontal axis at angle alpha.
The force (F), acting on the body parallel to the inclined plane, remains constant during the entire action. The friction friction coeffecient between the body and surface is μ.

A) Calculate the force (F) acting on the body, if in the motion of the body its velocity decreases from 6 m/s to 3 m/s

B) What is the work done in this segment?

 

[Femme_physics]

There were fewer mistakes in your posts if you typed in the calculations. And they were easier to read.

ehild

I just noticed that post. Well, it's tons more time-consuming to do it via typing. I'll try though to be as clear as I can, and show it typed whenever I can.

 

[I like Serena]

Good morning Fp!

No mistake. I believe your answer is correct.
(Unless ehild thinks otherwise. )

 

[ehild]

I just noticed that post. Well, it's tons more time-consuming to do it via typing. I'll try though to be as clear as I can, and show it typed whenever I can.

Well, it is very difficult to read your handwriting, but your comfort is the first.

Have you found the missing force? Hint: look at the solution of the previous problem.

ehild

 

[Femme_physics]

Good morning Fp!

No mistake. I believe your answer is correct.
(Unless ehild thinks otherwise. )

Neat ! So the work done is just

Fk x AB = 1879 x 30 = 56370 [N x m]Yes?

 

[Femme_physics]

Well, it is very difficult to read your handwriting, but your comfort is the first.

Have you found the missing force? Hint: look at the solution of the previous problem.

ehild

Well, yes, if I corrected the kN -> N thing it turns out 1420.28 [N]

I figured that was right, that's what I thought ILS was saying

Well, it is very difficult to read your handwriting, but your comfort is the first.

I'll try be clearer then. I normally write it big with a big marker, in this case though I can see why it's difficult. If you'll ask me to redo it typed I will

 

[ehild]

No mistake. I believe your answer is correct.
(Unless ehild thinks otherwise. )

I see only the applied force and friction.

ehild

 

[I like Serena]

I see only the applied force and friction.

ehild

You're right, so Fp's answer is wrong after all.
(Good that I made an exception clause! )

 

[Femme_physics]

Corrected, fixed

Thanks!

http://img217.imageshack.us/img217/5964/solved1.jpg
http://img823.imageshack.us/img823/1004/solved2.jpg

 

[I like Serena]

Good!