Dynamics - Using the coefficient of friction

AI Thread Summary
To lower a 260 kg safe down 20.0 m of skids at a constant speed from a height of 2.0 m, the coefficient of friction is 0.25. The frictional force must be calculated using the equation F = μN, where N is the normal force. Since the safe is moving at constant speed, the pulling force must balance the frictional force and the component of gravitational force acting down the skids. The discussion emphasizes the need to determine whether a pulling force is necessary or if the safe should be held back, along with calculating the required force parallel to the skids. Understanding these dynamics is crucial for ensuring safe handling of the load.
K.QMUL
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Homework Statement



You are to lower a safe of mass 260kg at constant speed downs skids 20.0m long, from a truck 2.0m high.
a) If the coefficient of friction between the safe and the skids is 0.25, do you need to pull the safe down or hold it back?

b)How great a force parallel to the skids is needed?

Homework Equations



F=μN

The Attempt at a Solution



Please see image
 

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