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An 55.0-N crate of apples sits at rest on a ramp that runs from the ground to the bed of a truck. The ramp is inclined at 30.0° to the ground.

I sketched the problem using a popular paint program. I seem to be having problems visualizing components of the normal force for some reason. I know by rote that 55cos(30) will give me the normal force but I do not know why. Could anyone help me see it?

By luck I was able to answer " What is the minimum possible value of the coefficient of static friction" by dividing 55cos(30) by 55sin(30).

The last part of the problem asks:

"The normal and frictional forces are perpendicular components of the contact force exerted on the crate by the ramp. What is the magnitude and direction of the contact force?"

Does anyone know what question wants me to do?

EDIT: I answered this problem correctly by asserting the magnitude and direction of the contact force is 55N and 90 degrees respectively. It was a lucky guess. Anyone know what this question is getting at?

Thanks!

Bob

http://img218.imageshack.us/img218/7973/frictionvu9.gif [Broken]

I sketched the problem using a popular paint program. I seem to be having problems visualizing components of the normal force for some reason. I know by rote that 55cos(30) will give me the normal force but I do not know why. Could anyone help me see it?

By luck I was able to answer " What is the minimum possible value of the coefficient of static friction" by dividing 55cos(30) by 55sin(30).

The last part of the problem asks:

"The normal and frictional forces are perpendicular components of the contact force exerted on the crate by the ramp. What is the magnitude and direction of the contact force?"

Does anyone know what question wants me to do?

EDIT: I answered this problem correctly by asserting the magnitude and direction of the contact force is 55N and 90 degrees respectively. It was a lucky guess. Anyone know what this question is getting at?

Thanks!

Bob

http://img218.imageshack.us/img218/7973/frictionvu9.gif [Broken]

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