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J.T.
Oct28-03, 11:16 PM
I have been stuck on this problem for so long... It's seriously driving me insane.

The problem:
An incline plane that makes an angle of 28 degrees to the horizontal is mounted on wheels. A small block of mass m=0.9kg rests on the plane, held there by a coefficient of static friction [mu]=0.73.
The plane is accelerating to the right. What is the minimum accleration in order that the block slides down the plane?

So far I've only been able to draw the free body diagram. After that, I realize I have to apply Newton's 2nd law to the vertical and horizontal components, but that's where I start having trouble. I don't really know how to separate out the components [:(]

Any help would be greatly appreciated! Thanks in advance.

sridhar_n
Oct28-03, 11:57 PM
Heres how u go about with the problem:

the vertical component of the acceleration is along the normal force and the horizontal component of the acceleration is along mgsin28 component. Thus a equilibrium, if a = min accln req by the mass to slide down:

μ*(masin28 + mgcos 28) = mgsin28 + macos28

From this a(0.73*sin28 - cos 28) = g(sin28 - 0.73*cos28)

Find out a by solving the above.

Got it???

Sridhar

J.T.
Oct29-03, 02:14 AM
Sorry for sounding like an idiot, but I'm not getting it.

I tried solving for a as you said, but I keep getting the wrong answer [:((] Maybe I'm just really bad at calculating numbers...

Thank you for the help anyways!

J.T.
Oct29-03, 02:32 AM
Sorry for sounding like an idiot, but I'm not getting it.

I tried solving for a as you said, but I keep getting the wrong answer [:((] Maybe I'm just really bad at calculating numbers...

Thank you for the help anyways!