# Barrels and Pipes

## Homework Statement

Michael is trying to raise a barrel using sections of pipe.The three objects are horizontal cylinders resting on level ground. The barrel has a mass of 100 kg and its diameter is 2.0m. Each pipe has a diameter of 0.50 m. What minimum horizontal force must his feet exert on the pipe to raise barrel from the ground? Neglect Friction.

## Homework Equations

Newton's first law, newton's second law, newton's third law...

## The Attempt at a Solution

well, i figure that the pipe in the corner against the wall has no acceleration, but because of newton's third law exerts a force equal to force applied onto the barrel (force contact). now, im just confused after where to go now.

i thought about it, and the distance between the two cylinders, pipe and barrel, must 1.5m.

thats as far as i got. PLEASE HELP! D:

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## Answers and Replies

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Delphi51
Homework Helper
Welcome to PF, dragon.
I suggest you draw a line from the center of the barrel to the center of each pipe, passing through the points where the pipes contact the barrel. The force of each pipe on the barrel will be along those two lines and will be partly horizontal and partly vertical. Draw the component of the applied force vector that is along the contact line and calculate its portion of the applied F using trigonometry (you will need the angle of the contact line above horizontal). Then multiply by the appropriate factor to get the vertical component of that force. Double it because you have an equal force from the other side. That should give you a number time F, which is equal to the weight of the barrel. Solve for F.